Vasal of the Seal vs Corvis the Corruptor

Overall comparison

HERO	Fraction	Element	Type	Rarity	Aura
Vasal of the Seal	Demonspawn	Force	HP	Legendary	HP 33% Place: All battles
Corvis the Corruptor	The Sacred Order	Magic	Defence	Legendary	Defence 30% Place: All battles

Stats comparison

HERO	LVL	STARS	HP	ATK	DEF	SPD	C.RATE	C.DMG	RESIST	ACC
Vasal of the Seal	60	6	21315	870	1288	98	15	50	40	20
Corvis the Corruptor	60	6	19155 -2160	903 +33	1398 +110	99 +1	15	50	40	20

Skills comparison

Vasal of the Seal	Abyssal Seal Formula: 0.25*HP Attacks 1 enemy. Places a [HP Burn] debuff on the target for 2 turns if they are under a [True Fear] debuff or a [Decrease ATK] debuff. Also places a [Shield] buff on this Champion for 2 turns equal to 10% of their MAX HP. Shield HP Burn	Infernal Darkness Formula: 0.27*HP Attacks all enemies. Has a 75% chance of placing a [True Fear] debuff and a 50% [Decrease ATK] debuff for 2 turns. Cooldown: 5 True Fear Decrease ATK 50%	Daemon Possession Balances the HP of all allies. The HP levels of all allies will be brought up to the level of the ally with the highest HP. After balancing HP, grants an Extra Turn. Cooldown: 6	Legion of Doom [P] Formula: -0.2DMG_MUL Formula: 0.2DMG_MUL Receives 20% less damage from Champions from the Banner Lord, High Elf, and Sacred Order Factions. If there are 2 or more Demonspawn Champions on the team alongside this Champion, increases the C. DMG of all Demonspawn Champions on the team by 20%. [C. DMG increase only works when this Champion is alive.]
Corvis the Corruptor	Reductive Process Formula: 3.1*DEF Attacks 1 enemy. Has a 40% chance of placing a 50% [Decrease ATK] debuff for 2 turns. Decrease ATK 50%	Medical Miracle Formula: 1.9DEF Formula: 1.9DEF Attacks all enemies 2 times. The first hit increases the duration of all enemy debuffs by 1 turn. The second hit increases the duration of all ally buffs by 1 turn. Cooldown: 4	Field Research Formula: 2DEF Formula: 2DEF Attacks all enemies 2 times. Each hit has a 75% chance of placing two 5% [Poison] debuffs for 2 turns. After attacking, places a 25% [Poison Sensitivity] debuff on enemies under 2 or more [Poison] debuffs. Cooldown: 5 Poison Sensitivity Poison 5%	Curious Draught [P] Formula: (EffectsAppliedOnTargetCountOfKind(ContinuousDamage_KindId)<5)(-0.05DMG_MUL)EffectsAppliedOnTargetCountOfKind(ContinuousDamage_KindId)+(EffectsAppliedOnTargetCountOfKind(ContinuousDamage_KindId)>=5)(-0.25*DMG_MUL) Decreases the damage enemies under [Poison] debuffs inflict (5% less damage per [Poison] debuff, stacks up to 25%).