Ardent Elementalist

When Ardent Elementalist enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Phyrexian Vivisector

Whenever a creature you control dies, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Warehouse Tabby

Whenever an enchantment you control is put into a graveyard from the battlefield, create a 1/1 black Rat creature token with "This creature can't block."
{1}{B}: Warehouse Tabby gains deathtouch until end of turn.

Energy Refractor

When Energy Refractor enters the battlefield, draw a card.
{2}: Add one mana of any color.

Living Lightning

When Living Lightning dies, return target instant or sorcery card from your graveyard to your hand.

Swamp

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Undying Malice

Not Dead After All

Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Mountain

Gnawing Crescendo

Creatures you control get +2/+0 until end of turn. Whenever a nontoken creature you control dies this turn, create a 1/1 black Rat creature token with "This creature can't block."

Akki Ember-Keeper

Whenever a nontoken modified creature you control dies, create a 1/1 colorless Spirit creature token. (Equipment, Auras you control, and counters are modifications.)