Challenge Mode


 * Challenge mode costs 10 runes to enter and provides players with 2 packs (16 cards) that the player uses only for that challenge mode.
 * Once you start the Challenge Mode, you will get 16 cards randomly. But you will get fixed cards' rarity; 10 Elite cards, 4 Epic cards, and 2 Legendary cards. You will need to design your deck with these 16 cards.
 * All the heroes are level 11 and the player must form his team including subs.
 * You can reset skills freely in challenge mode.
 * Each time you play you will be rewarded based on how many floors you clear. You will receive 50 gold per floor and a chance of a Shadow Pack (Single) for each Shadow boss defeated.
 * There are also weekly rewards based on rank of how many bosses where defeat compared to others.

Rewards

 * Rewards will be given at every Thursday 5 p.m. (KST, GMT/UTC + 09:00) automatically.
 * After that, challenge mode rank will be reset.

Guide (Skigget 19)
Sections - Challenge Mode Overview - General Strategies - General Team Comp - Major Bosses - Normal Bosses

Challenge Mode Overview

 * 10 Runes per entry. Ends if you lose 3 battles.
 * You will draw 16 cards, of which 2 are Legendaries, 4 are Epics, and 10 are Elites.
 * You can choose 8 of those cards to bring with you. You do not get to keep or use these cards outside of Challenge Mode.
 * Rewards
 * 50 Gold per floor cleared upon completion.
 * 1 Shadow Card pack (contains only 1 card per pack) for every  Shadow boss  that is killed upon completion.
 * Weekly gems and card rewards based on ranking of highest cleared floor, given out on Thursday.
 * Every 5th floor (5F, 10F, 15F, etc) is a "Major" boss that seems to be tougher than the rest. This boss is the same every time you enter Challenge mode.
 * All other floors contain a random "Normal" boss, though some bosses will generally appear on higher floors.
 * For example, Black and Crimson Dragons usually appear past 10F.
 * Bosses will get stronger and deal more damage as you reach higher floors.
 * Shadow bosses  randomly appear in place of a "Normal" boss.  Shadow bosses  can be anywhere from a Level 50 Expert to Level 99 Legendary.
 * The rarity of the  Shadow boss  does not appear to affect the type of card you pull from the Shadow Card pack.
 * A guaranteed  Shadow boss  will appear on 11F, 21F, 31F, and 41F. That means you are guaranteed at least 4 Shadow Card packs if you make it to the end (assuming 50F is the highest).
 * Shadow Card packs contain Novice to Legendary Shadow cards, and is the only source for Shadow cards at the moment.
 * I recommend saving all your Shadow cards regardless of rarity. If you manage to get 3 of the same card, you can fuse them to upgrade their rarity, and eventually get a Legendary even if you don't pull one from the Pack.

General Strategies
You don't need to use all 11 skill points. Although you have access to them, sometimes it's better to leave some unused. Here are a few situations:
 * Utilizing Basic Attacks. If your card has a good Basic Attack (like Legendaries, or Healers) then you want to only put points into about 3 different skills so that the card can still use its Basic Attack. If you have too many skills, it won't have any free time to use the Basic Attack because of all the available skills.
 * Likewise, if you need your Archers to use Silence Arrow effectively, only put points into Silence Arrow, Toughness, and maybe Burst Shot. It won't get stuck casting other skills when it needs to use Silence Arrow.
 * Removing risky skills. For example, if a boss Counters all Fire skills, you will want to make sure you don't use any Fire skills.
 * Removing skills with negative effects. For example, Paradox is great for most boss fights, but if you're fighting a boss that can do High True damage, then you want to not use it.
 * Quality over quantity.  Generally, it is usually better to have fewer maxed out skills than many partially maxed skills.
 * This is true for most buffs that increase in duration, like Haste. Level 1 is 5 seconds, which is not long enough for anything.
 * There are exceptions to this rule. Here are some situations where you may want to purposely use a lower level skill:
 * Arcane Prophecy Shaman only needs Level 1 Arcane Shock to trigger Survival Knowledge
 * Mage's Polymorph is still useful at level 1 as a quick Stun.
 * Berserk Warrior's Blood Lust can be adjusted between level 1 to level 3 depending on how many healers you have or how dangerous the boss is.
 * Arcane Mage's Fire/Ice Charge at level 1 is still very powerful without severely impacting the rest of your team.
 * Defense Warrior's Intervene is useful but doesn't trigger often enough to warrant level 3.
 * Triggering Prophecy Shaman heals . Arcane Prophecy Shamans are great multi-target healers, if you get one that doesn't have Survival Knowledge, it's a bit trickier to trigger the special. Here are some combos that can trigger the heal:
 * Anti Cold Plan (Fire)
 * Snipe Archer - Fire Shot
 * Defense Warrior - Iron Shield
 * Sacrifice Knight - Conversion
 * Anti Heat Plan (Ice)
 * Guardian Knight - Bounce
 * Sacrifice Knight - Transmission
 * Snipe Archer - Frost Shot
 * Defense Warrior - Copper Shield
 * Detection (Nature)
 * Defense Warrior - Wooden Shield
 * Boss strength . When you click on the boss info in the battle report screen, it will show you the amount of damage that the boss does  by default.  This is important because bosses get stronger as you get higher, but that is not shown on this screen. A 1F Hatchling may be weak, but a 31F Hatchling will do a lot of damage with its Basic Attack. Once the fight starts, you can click on the boss card to see its actual stats for that floor.

General Team Comp

 * Here are some team composition strategies that I tend to look for whenever I first start Challenge Mode. Since you can only bring 8 cards with you, make sure you have specific ways to handle some of the harder boss fights.
 * Phase 3 Stunner
 * There are three Dragon bosses that have a Phase 3 Pierce skill that does Very High damage to the 1st, 2nd, and 3rd threat. The best way to beat these bosses is to have a card that can Counter or Stun their Phase 3 skill.
 * Best Options if Available
 * Fire or Ice Mage  w/ Phase 3 Cancel
 * Hunt Archer  w/ Silent Arrow
 * Battle Assassin  w/ Faint
 * Defense Warrior  w/ Phase 2 or 3 Copper/Wooden/Mana Shield. Iron Shield can be used as well, but is risky if fighting Crimson Dragon.
 * Alternatives
 * Fire or Ice Mage  w/ Polymorph
 * Berserk Warrior  w/ Level 1 Skull Crush - Only level 1 because he will use Skull Crush regardless of where he is, so you don't want him to stun himself for 6 seconds.
 * Snipe Archer  w/ Push - Won't stop Pierce, but may delay it long enough for your healer to do get a heal off or for a  Hunt Archer  to finish casting Silence Arrow.
 * Healers
 * Types of Healers Mentioned in This Guide.
 * 1st Threat Ally -  Divine Priest ,  Guardian Knights ,  Sacrifice Knights.
 * Multi-Target Healer -  Prophecy Shaman . Other healers may have a Special that are multi-target.
 * Lowest HP Ally -  Prophecy Shaman . Other healers have a Basic Attack that targets lowest HP ally.
 * Self Healers -  Prophecy Shaman  and  Guardian Knights  have heals that target another ally and itself.
 * Prophecy Shaman  and  Sacrifice Knights  have Nature element heals.  Divine Priest and  Guardian Knights  have Holy element heals.
 * Keep this in mind because some bosses have skills that can be deadly if your team casts Holy or Nature skills. Most healers will usually have a Skill or Special Heal that is a different element.
 * Tanks
 * Primary Tanks - These the good defense and resists, and a way to generate Threat of some kind.
 * Defense Warrior  and  Guardian Knights
 * Sub-Tanks - These make good backup Tanks, or even used as primary tank if you have extra healers.
 * Berserk Warrior ,  Sacrifice Knights .  Revenge Knights.
 * Situational Tanks - Only use them if your team has no other tanks what-so-ever and you're fighting bosses that do Low to Medium damage.
 * Battle Assassin  - Need to max Shadow Cape
 * Legendary Ice or Fire Mage  +   Prophecy Shaman  - Max Polymorph. Legendary only because they can stun by default if they have Arcane buff.
 * Prophecy Shaman  - Basic Heal can heal itself twice if its the 1st threat. But low defense.
 * Highest HP Legendary - Worst case scenario, your highest HP Legendary card can serve as a tank because they usually have the best stats.
 * Debuffers
 * Some bosses have skills that can be deadly if they have specific elemental debuffs on them when they use the skill. Keep this in mind so you don't have too many debuffers on your team and end up making those boss fights harder.
 * Nature -
 * Curse Warlocks - Fatal Poison I, Fatal Poison II, Poison, Contagion
 * Spirit Shaman - Forgot name, its the Nature version of Mystic of Nature
 * Berserk Warrior - Poison Sword
 * Hunt Archer - Poison Arrow
 * True -
 * Legendary Hunt Archer - Basic Attack
 * Legendary Berserk Warrior - Basic Attack
 * Legendary Ambush Assassin - Basic Attack
 * Legendary Battle Assassin - Basic Attack
 * Battle Assassin - Incision I, Incision II
 * Snipe Archer - Push
 * Revenge Knight - Divine Attack I, Divine Attack II
 * Arcane
 * Hunt Archer - Check Fire
 * Arcane Mage - Magic Arrow
 * Berserk Warrior - Magical Sword
 * Spirit Shaman - Electric Shock, Mystic of Nature
 * Fire
 * Berserk Warrior - Burning Sword
 * Hunt Archer - Flare
 * Ice Mage - Burn
 * Ice
 * Berserk Warrior - Frozen Sword
 * Hunt Archer - Warning Shot
 * Ice Mage - Freeze
 * Dark
 * Legendary Destruction Warlocks - Basic Attack
 * Legendary Darkness Priest - Basic Attack
 * Curse Warlocks - Deprave, Curse
 * Holy
 * Sacrifice Knight - Denounce a Heresy
 * Darkness Priest - Life Drain, Dark Despersion
 * What do you do if you have No Healers, or No Tanks?
 * Don't give up. Focus on the strength of your Legendaries, or build a team that's all damage.
 * I recently drew 16 cards with no Tanks or Healers. Ended up with a team of 1 Defense Warrior, 3 Berserk Warriors, 1 Ambush Assassin, and had 2 Snipe Archers and 1 Hunt Archers as sub-cards. It managed to get all the way to 24F before losing to Succubus. In the end, I won 1200 gold and 4 Shadow cards.

Major Bosses
These bosses appear every 5th floor (5F, 10F, 15F, etc) and will always appear on the same floor.

5F - DRAKE

 * Basic Attack:  Medium damage to 1st threat enemy.
 * Notable skills
 * Boss will stun multiple targets during phase 1-3, and then spam multi-target high damage moves phase 4-5.
 * Strategies
 * First major boss, very weak. Focus on phase 1-3 damage skills to kill him early.

10F AND 30F - OGRE MAGE

 * Basic Attack:  Very High damage to 1st threat enemy.
 * Notable skills
 * Dark Arrow  - Comes in two variants
 * (4th Phase) - Damage to 2nd to 5th enemies, restores his HP for each target with Holy buff or Dark Debuff.
 * (2nd Phase) - Damage to 4th and 5th enemies, restores his HP for each target with Holy buff or Dark Debuff.
 * (2) Observation - Dark damage per sec over 30sec, 15sec cooltime.
 * Strategies
 * Need a strong tank in position 1. He hits very hard.
 * (4th Phase) Dark Arrow version is much easier.
 * Focus on phase 1-3 damage skills. He should be able to be killed early if you can keep your tank alive.
 * (2nd Phase) Dark Arrow version is harder in my opinion.
 * Avoid any team wide Holy buff (like Priest's Reinforcement).
 * If you have Healers with Holy skills, put them in position 2 and 3 to avoid Dark Arrow restoring HP to boss.
 * Don't bother with Counter Attacks or Stuns. All his skills cannot be countered, except for Observation and Magic Resist. It is easier to dispel Observation.

15F AND 35F - FIRE SPIRIT

 * Basic Attack:  Low/medium damage over 4 seconds, and reduces healing. No cooltime.
 * Notable skills
 * (2) Scorch  - Counter Attack. Reduce casting speed of Ice skills.
 * Strategies
 * Biggest threat is his  Basic Attack, it will most likely kill the 1st target during Phase 1. On  35F , he can kill two allies during Phase 1 if unprepared.
 * On  15F, Prioritize damage over defense/heals, especially early phase damage skills to kill him quickly.
 * Avoid using skills that gain Threat (like Taunt). Let your team switch positions throughout the fight so that his  Basic Attack  spreads around.
 * Also prioritize multi-target heals and lowest HP ally heals over 1st threat ally heals.
 * Phase 1 specials/skills that boosts Fire resists are extremely useful here.
 * On  35F, only focus on damage if you have a way to deal high damage during Phase 1 (like 4 Curse Warlocks.) Otherwise, focus on surviving to Phase 2 or 3 where more damage skills become available.

20F AND 40F - WATER SPIRIT

 * Basic Attack:  Low/Medium damage to 1st threat enemy.
 * Notable skills
 * (1) Aqua Stream  - Stun 5th enemy and do damage over 3sec, and then deal additional dmg after 3sec. Boss is immune while casting.
 * (3) Defiance  - Counter Attack. If enemy uses Fire, Dark, Arcane skill, deal damage and become immune to that element for 3sec.
 * Strategies
 * She spams Aqua Stream during Phase 1 and 2. Put your sub-tank or an ally that can heal itself in 5th position.
 * Avoid Fire, Dark, and Arcane skills if possible.
 * Make sure your healer only has 2 or 3 skills so that it can use its basic heals on the lowest HP ally.

25F - SUCCUBUS

 * Basic Attack:  Low damage to all enemies, low heal to all allies.
 * Notable skills
 * (1) Chaos Chamber  - Summon Guardian Knight, Arcane Mage, Ambush Assassin, Darkness Priest
 * (2) Bite  - Reduce Heals to all enemies by 200 permenantly. 50% increase to Defense and Resists to all Allies.
 * (3) Mirage  - Counter Attack. Dispel True debuff, permanent 15% increase in Defense to all allies.
 * (4) Sit Down!  - Counter Attack. Dispel Dark, Fire, Ice debuffs. Permanently reduce Healing, Attack Power, Spell Power to all enemies.
 * Strategies
 * Probably the hardest fight and hardest to prepare for.
 * Chaos Chamber can't be stopped. She will summon 4 allies. They have the same moves as their regular Shadow cards do.
 * Because of Mirage, cards with True debuffs will end up causing the boss to get extremely resistant to True attacks.
 * If available, Arcane and Nature attacks are most effective.
 * All heals are reduced. It is almost more useful to go all-damage for this fight.
 * I've had success with Arcane Mage buffed with Check Fire and Fire/Ice Charge, 3x or 4x Curse Warlock teams, multiple Revenge Knights, multiple Berserk Warriors, 2 Snipe Archers + 2 Hunt Archers.

Normal Bosses
These bosses can randomly appear on any floor that is not specific to a Major Boss. Because bosses get stronger as you get higher, I gauged their Basic Attack's strength relative to each other.

COASTAL DRAKE

 * Basic Attack:  Low damage to 1st threat enemy.
 * Notable skills
 * Paralyze  - Counter Attack. Stuns allies casting Ice skill and increases Ice skill's cooltime by 15s
 * Strategies
 * Weak boss, even if he shows up on the higher floors.
 * Limit amount of Ice skills on your team.
 * Any team with 1 healer and at least 3 damage dealer can kill him easily.

WITCH

 * Basic Attack:  Medium damage to 1st threat enemy.
 * Notable skills
 * Blasphemy  - Counters all Priest and Knight skills
 * Strategies
 * Weak boss, even if she shows up on the higher floors.
 * Blasphemy is not as dangerous as it sounds, even with a team of Revenge Knights.
 * Any team with 1 healer and at least 3 damage dealer can kill her easily.

HATCHLING

 * Basic Attack:  High damage to 1st threat enemy.
 * Notable skills
 * (1) Expose Weakness  - Counter Attack. If Hatchling has two opposing debuffs (Nature and Arcane, or Fire and Ice, or Holy and Dark) deal 5% of max HP to itself.
 * (3) Trickery  - Increase threat of 5th threat enemy by 1000%, lowers threat of 1st threat enemy by 100%
 * Strategies
 * Expose Weakness is useful if your team can trigger it with two different elemental debuffs.
 * Don't go out of your way to target Expose Weakness though. It's on a 15sec cooltime and isn't enough to kill him even if you trigger it every 15sec.
 * Any team with 1 healer, 1 tank and 3 damage dealer can kill him easily.
 * Keep a sub-tank or any your second highest HP card in the 5th position, so that Trickery doesn't grab a vulnerable ally.

ARMORED TROLL

 * Basic Attack:  Medium damage to 1st threat enemy.
 * Notable skills
 * (2) Smash  - Damage to 2nd threat enemy.
 * Bash  - Damage to lowest threat enemy, and stuns for 10sec.
 * Strategies
 * Boss likes to spread his damage around. All his skills target your cards in different positions or multiple cards.
 * Use a multi-target healer if you have it. If it not, make sure healer has only a few skills so that it can still use the basic heal on lowest HP ally.
 * Keep healer out of position 5, so it doesn't get stunned by Bash.

TROLL

 * Basic Attack:  High damage to 1st threat enemy.
 * Notable skills
 * (2) Smash  - High damage to lowest threat enemy, and stuns for 10sec.
 * (3) Stink  - High damage to all enemies.
 * Strategies
 * Same strategy as Armored Troll, but he does more damage.
 * Remove any skills that lower defense (ie Curse Warlock's Paradox, Arcane Mage's Charge Fire, etc).

SEA BEAST

 * Basic Attack:  Low damage to 1st threat enemy.
 * Notable skills
 * (2) Adapt  - Counter Attack. If HP is less than 20%, restore 100% HP. If it has any debuff, become immune to that element.
 * Strategies
 * Remove any skills that apply a debuff. Some Basic Attacks apply debuff (especially Legendary cards) so check those as well.
 * If you can't completely remove debuff skills without jeopardizing damage, try to group the debuffs into an early phase and a late phase.
 * For example, if your team has 3 Curse Warlocks, 1 Revenge Knight and 1 Hunt Archer.
 * Max Fatal Poison, Fatal Poison 2, and Incoming Death. Max Burst Shot, Multi Shot, Toughness. Max Final Strike and the Special.
 * This will let your Curse Warlocks deal most of the damage early on to trigger Adapt. If boss becomes immune to Nature, then your Revenge Knight and Archer can finish it off.

SEA WITCH

 * Basic Attack:  Low damage to 1st threat enemy.
 * Notable skills
 * (1) Aqua Arrow  - Deals 25% of their Max HP to all enemies. Resets her special.
 * (3) Pin Down  - Counter Attack. If enemy is casting Fire, Arcane, or Nature skills, stun for 1sec. Increase resist by 600% for 3sec.
 * (4) Weapon Throw  - Deals 30% of their Max HP and additional flat dmg to 1st threat enemy. Cooltime 1s.
 * Strategies
 * She has some dangerous skills, but Pin Down is really the only one you may need to shuffle your team around for.
 * Remove any Fire, Arcane, or Nature skills. Pin Down has a short cooltime, and will actually pin them down.
 * Focus on phase 1-3 damage skills. She should be killed before Phase 4 to avoid Weapon Throw.
 * Use Holy healers, and make sure healer has only a few skills so that it can still use the basic heal on lowest HP ally.
 * Multi-target healers tend to use Nature skills, so may get caught by Pin Down.

OGRE WARRIOR

 * Basic Attack:  Medium damage to 1st threat enemy.
 * Notable skills
 * Flank Strike  - Medium damage to lowest threat enemy. If their HP is less than 50%, cast again. 1sec cooltime.
 * (4) Smash  - High dmg to 2nd threat enemy. If their HP is less than 50%, cast again.
 * Strategies
 * He will spam Flank Strike in early phases. Put sub-tank, or a healer that can heal itself (ie, Guardian Knight, Prophecy Shaman) in the 5th position
 * Healers that can heal lowest HP ally is usually enough for this fight. A balance team can out-damage and kill him before phase 4.

CYCLOPS

 * Basic Attack:  High damage to 1st threat enemy.
 * Notable skills
 * Ignore  - Reduce 100% threat of 1st threat enemy.
 * No phase 3 skill.
 * Strategies
 * Weak boss, even if he shows up on the higher floors.
 * Any team with 1 healer and at least 3 damage dealer can kill him easily.
 * If your tank doesn't have a way to generate threat, remove any skills that lower defense (ie Curse Warlock's Paradox, Arcane Mage's Charge Fire, etc). This way, if a weaker ally moves into the 1st position, it can survive a couple hits.

ARMORED CYCLOPS

 * Basic Attack:  Low damage to 1st threat enemy.
 * Notable skills
 * (2) Gaze  - Deals damage to lowest threat enemy over several seconds, and additional medium damage afterwards.
 * (3) Petrify  - Stun enemy with lowest CON.
 * Strategies
 * Lower damage than regular Cyclops, but more troublesome.
 * Put sub-tank, or a healer that can heal itself (ie, Guardian Knight, Prophecy Shaman) in the 5th position
 * Check your cards and note which one has the lowest CON. If it's your healer, you may want to take along another card that can do damage as well as heals (ie, Prophecy Shaman with maxed Force of Nature, Revenge Knight, Spirit Shaman with maxed Serendipity, etc)

BLACK DRAGON

 * Basic Attack:  Low damage to 1st threat enemy.
 * Notable skills
 * (1) Fear  - Reduce threat by 100%, and reduce attack power and spell power by 50%.
 * (2) Sneer  - Counter Attack. Stun target casting Dark skills and increase that skill's cooltime by 15sec. 5sec cooltime.
 * (2) Cruelty  - Deals low damage to lowest threat ally. Reset cooltime if target has Dark buff or casting Dark skill.
 * (3) Pierce  - Very High dmg to 1st, 2nd, and 3rd threat enemy.
 * (4) Curse  - Damage to all enemies over 30sec.
 * Strategies
 * Need Phase 3 Stunner (Phase 3 Cancel, Silent Arrow, Faint, Phase 3 Shields.) Alternates listed above can be used, but are less reliable and may require multiple.
 * If you do not have any Phase 3 Stunner, bring multi-target healers.
 * If you do not have a Phase 3 Stunner or a multi-target healer, then go all out damage dealer. It is possible to kill the boss before Phase 3, or at least survive a couple of Pierce.
 * Don't bother with threat generating skills on your tank because Fear will keep repositioning your team. And even Mages and Warlocks can tank him long enough for him to use Fear again.
 * Remove all Dark skills. This will make his Phase 2 negligible.
 * Don't bring too many healers or support cards and neglect damage.
 * Focus on phase 1-3 damage skills. Need to kill him before Phase 4 because Curse will wreck more havoc than Pierce.
 * Because he starts the fight with Fear, and can use it roughly every 30 seconds, consider repositioning your team.
 * Weakest card or healer in 1st, damage dealers in 2nd and 3rd, any Alternate stunners in 4th, and late phase damage dealers in 5th.
 * This way, your healer will immediately get hit by Fear at the start of the fight and move to the back. Then in Phase 1 and 2, your damage dealers can dish out damage and soak up the boss's weak attacks. By Phase 3, he will have used Fear on both your damage dealers, which will move your Stunner into the 1st position, letting them use their Stun skill if available. Your late phase damage dealer (cards that focus on doing damage from Phase 3 and later like Snipe Hunters) will then be available to deal damage and clean up.

CRIMSON DRAGON

 * Basic Attack:  Medium damage to 1st threat enemy.
 * Notable skills
 * (1) Fear  - Reduce threat by 100%, atk/spell by 50%
 * (2) Sneer  - Counter - 1s cooltime. If same threat cast fire, stun all enemies, increase cooltime by 15s
 * (3) Pierce  - Very High dmg to 1st, 2nd, and 3rd threat enemy.
 * (4) Boil  - If ice debuff, increase cooltime of ice skill by 300s
 * Strategies
 * Same strategies as Black Dragon. But instead of Dark skills, remove all Fire Skills. His Sneer stuns ALL allies, and is even more dangerous.
 * Basic Attack deals more damage than Black Dragon, so be careful wth low HP cards. Remove any skills that lower Defense.

BONE DRAGON

 * Basic Attack:  Low damage to 1st threat enemy.
 * Notable skills
 * (1) Resist  - If HP is below 20%, restore 50% HP, dispel all debuffs, counter all skills. Increase attack speed, cooldown speed, and attack power for 30sec.
 * (2) Frozen Storm  - Deal 70% of their current HP to all enemies.
 * (2) Chromatic Scale  - Counter Attack. Dispel all debuffs, deal low/med dmg to all enemies for each debuff type. If Fire, Holy, Arcane, reset skill cooltime.
 * (3) Pierce  - Very High dmg to 1st, 2nd, and 3rd threat enemy.
 * Strategies
 * The toughest of the 3 Pierce Dragons, in my opinion.
 * Need Phase 3 Stunner and must remove all debuff skills (especially Fire, Holy, Arcane debuffs) or atleast limit to just one element.
 * Do not neglect damage. If removing all debuffs causes you to lose majority of your damage skills, then its better to take the risk of having debuffs. But limit to just one element.
 * Example, if most of your team's damage comes from Revenge Knights, remove other debuffs, but keep any True debuff moves like Divine Attack.
 * Do not use any Fire, Holy, or Arcane debuffs. This will let him spam Chromatic Scale and kill everyone.
 * Frozen Storm won't kill you, but it will make it easier for Chromatic Scale and Pierce to kill you if they're not stopped.
 * Use a multi-target healer if you have it. If it not, make sure healer has only a few skills so that it can still use the basic heal on lowest HP ally.
 * It is possible to kill him without Resist triggering. This happens if he gets stunned for too long and your team somehow deals over 20% of his HP in damage within that time. But this is rare, don't rely on it. Assume that he will use Resist.