Because of its rarity, Corruption doesn't feel very strong in this game. If you could get it more consistently, you could play your early game toward it, taking cards like Shrug It Off and Dark Embrace which played very well with it. But because it's so unusual to find, I'm usually not taking many of those cards, and have other plans for how to play the Energy Cost on the cards I need by the time it's offered to me.
Basically makes all your blocks free so you can spend energy on attacks. You should have a plan to win the fight by the time you run out of block cards.
Gain 5 Block. You receive 50% less damage from Vulnerable enemies this turn.
Deal 8 damage to ALL enemies. Deals 2 additional damage for each other Attack you've played this turn.
Skills cost 0 . Whenever you play a Skill, Exhaust it.
At the start of your turn, lose 1 HP and gain 8 Block.