Commander creatures you own have "Whenever this creature becomes tapped, it and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn." (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Each spell you cast that's a Demon, Horror, or Nightmare costs {1} less to cast. Whenever you cast a spell, if the amount of mana spent to cast it was less than its mana value, target opponent loses life equal to the difference.

Flying At the beginning of your upkeep, mill a card. Threshold — As long as seven or more cards are in your graveyard, this creature gets +1/+1 and has "At the beginning of your end step, exile two cards from your graveyard."

Menace At the beginning of your first main phase, you may sacrifice a creature. When you do, choose a nonland card name, then target player reveals their hand and discards all cards with that name.

Horrors you control have menace. Whenever a Horror you control deals combat damage to a player, that player mills that many cards. At the beginning of your end step, choose target artifact or creature card in an opponent's graveyard that was put there from their library this turn. Put it onto the battlefield under your control.

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards. Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Whenever a creature you control becomes blocked, you may return it to its owner's hand. Whenever one or more creatures you control deal combat damage to a player, draw a card.

Aberrant Tinkering — When this creature enters and at the beginning of your upkeep, each Horror you control gains all activated abilities of target artifact an opponent controls until end of turn. You may spend blue mana as though it were mana of any color to activate those abilities.

Flash Flying Exploit (When this creature enters, you may sacrifice a creature.) When this creature exploits a creature, counter target spell, activated ability, or triggered ability.

When this creature enters, destroy target creature an opponent controls.

This creature can't be blocked. Whenever this creature deals combat damage to a player, choose one that hasn't been chosen — • Put two +1/+1 counters on this creature. • Draw a card. • This creature becomes a copy of another target creature you control.