Rock Breaker vs Gravechill Killer

Overall comparison

HERO	Fraction	Element	Type	Rarity	Aura
Rock Breaker	Dwarves	Spirit	Defence	Epic	Defence 30% Place: Arena
Gravechill Killer	Undead Hordes	Magic	Attack	Rare	-

HERO	LVL	STARS	HP	ATK	DEF	SPD	C.RATE	C.DMG	RESIST	ACC
Rock Breaker	60	6	18495	716	1354	91	15	50	75	0
Gravechill Killer	60	6	13545 -4950	1233 +517	892 -462	96 +5	15	50	30 -45	10 +10

Rock Breaker	Whirling Hammers Formula: 2.5DEF Formula: 0.04SKILL_USED_CURRENT_ROUND*B_DEF Formula: 0 Attacks 1 enemy. Increases this Champion's DEF by 4% each time this Skill is used. Stacks up to 20%.	Chest Thump Has a 75% chance of placing a [Provoke] debuff on all enemies for 1 turn. Places a [Counterattack] buff on this Champion for 2 turns. Cooldown: 4 Counterattack Provoke	Iron Hide [P] Formula: -0.5*DMG_MUL Has a 25% chance of decreasing damage inflicted on this Champion by 50% each time this Champion is attacked.
Gravechill Killer	Freezing Toxin Formula: 3.9*ATK Attacks 1 enemy. Has a 40% chance of placing a 5% [Poison] debuff for 1 turn. Poison 5%	Blood Chill Formula: 6.8*ATK Attacks 1 enemy. Has a 75% chance of placing a 30% [Decrease DEF] debuff for 2 turns. Has a 75% chance of placing a 60% [Decrease DEF] debuff instead if the target is under a [Poison] debuff. Cooldown: 4 Decrease DEF 60% Decrease DEF 30%	Icy Veins Formula: 2.65*ATK Attacks 1 enemy 2 times.Each hit places a 2.5% [Poison] debuff for 2 turns. Places a 5% [Poison] debuff instead if the target is under a [Poison Sensitivity] debuff. Cooldown: 5 Poison 2.5% Poison 5%