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

Flying
When this creature enters, for each opponent, you may cast up to one target instant or sorcery card from that player's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When this creature enters, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.

Flying, trample
Whenever a Dragon you control attacks, it gains double strike until end of turn.

Flying, deathtouch
When this creature enters, create four 1/1 green Insect creature tokens with flying and deathtouch.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)
Destroy all nontoken creatures.

Flying
When this creature enters, you may destroy target creature.
Whenever a nontoken creature an opponent controls dies, create a tapped 2/2 black Zombie creature token.

Flying
When this creature enters, you may have it fight target creature you don't control.
Whenever a creature you control fights, put two +1/+1 counters on it at the beginning of the next end step.

At the beginning of each upkeep, this creature deals 3 damage to any target.

At the beginning of each upkeep, create a 1/1 green Saproling creature token.

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

This spell costs less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Create X 1/1 white Pegasus creature tokens with flying, where X is your life total.