Book Devourer

Whenever this creature deals combat damage to a player, you may have it deal 3 damage to target creature that player controls.

Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

Flying

Whenever this creature deals combat damage to a player, each player discards their hand, then draws seven cards.

Flying

Whenever Crosis deals combat damage to a player, you may pay . If you do, choose a color, then that player reveals their hand and discards all cards of that color.

Flying, trample

Whenever this creature deals combat damage to a player, you may collect evidence X. When you do, this creature deals X damage to each creature and planeswalker that player controls. (To collect evidence X, exile cards with total mana value X or greater from your graveyard.)

Whenever this creature deals combat damage to a player, you may destroy target artifact that player controls.

Flying, haste

Whenever this creature deals combat damage to a player, you gain 1 life and draw a card.