Mindwrack Demon | Creature | Demon | Flying, trample
When Mindwrack Demon enters the battlefield, mill four cards.
Delirium — At the beginning of your upkeep, you lose 4 life unless there are four or more card types among cards in your graveyard. | Matt Stewart
Relentless Dead | Creature | Zombie | Menace (This creature can't be blocked except by two or more creatures.)
When Relentless Dead dies, you may pay {B}. If you do, return it to its owner's hand.
When Relentless Dead dies, you may pay {X}. If you do, return another target Zombie creature card with mana value X from your graveyard to the battlefield. | Ryan Yee
Olivia, Mobilized for War | Legendary Creature | Vampire Knight | Flying
Whenever another creature enters the battlefield under your control, you may discard a card. If you do, put a +1/+1 counter on that creature, it gains haste until end of turn, and it becomes a Vampire in addition to its other types. | Eric Deschamps
The Gitrog Monster | Legendary Creature | Frog Horror | Deathtouch
At the beginning of your upkeep, sacrifice The Gitrog Monster unless you sacrifice a land.
You may play an additional land on each of your turns.
Whenever one or more land cards are put into your graveyard from anywhere, draw a card. | Jason Kang