Whenever Kami of Mourning enters the battlefield, target creature you control or creature card in your graveyard perpetually gains "Whenever a creature you control with greater mana value than this card dies, return this card from your graveyard to the battlefield tapped."

Vigilance

Disturb (You may cast this card from your graveyard transformed for its disturb cost.)

Defender

When Wall of Mourning enters the battlefield, exile a card from the top of your library face down for each opponent you have.

Coven — At the beginning of your end step, if you control three or more creatures with different powers, put a card exiled with Wall of Mourning into its owner's hand.