Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card.

Whenever an opponent casts a spell, Kaervek deals damage equal to that spell's mana value to any target.

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

At the beginning of your upkeep, you lose 1 life and amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.) Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.