Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Sigarda's Summons

Creatures you control with +1/+1 counters on them have base power and toughness 4/4, have flying, and are Angels in addition to their other types.

Inspired Idea

Cleave {3}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Draw three cards. [Your maximum hand size is reduced by three for the rest of the game.]

Mirrorhall Mimic // Ghastly Mimicry

Copy

Mirrorhall Mimic

You may have this creature enter as a copy of any creature on the battlefield, except it's a Spirit in addition to its other types.
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Ghastly Mimicry

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except it's a Spirit in addition to its other types.
If Ghastly Mimicry would be put into a graveyard from anywhere, exile it instead.

Necroduality

Whenever a nontoken Zombie you control enters, create a token that's a copy of that creature.

Overcharged Amalgam

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.

Patchwork Crawler

{2}{U}: Exile target creature card from your graveyard and put a +1/+1 counter on this creature.
This creature has all activated abilities of all creature cards exiled with it.

Winged Portent

Cleave {4}{G}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Draw a card for each creature you control [with flying].

Cemetery Desecrator

Menace
When this creature enters or dies, exile another card from a graveyard. When you do, choose one —
• Remove X counters from target permanent, where X is the mana value of the exiled card.
• Target creature an opponent controls gets -X/-X until end of turn, where X is the mana value of the exiled card.

Concealing Curtains

Defender
{2}{B}: Transform this creature. Activate only as a sorcery.

Revealing Eye

Menace
When this creature transforms into Revealing Eye, target opponent reveals their hand. You may choose a nonland card from it. If you do, that player discards that card, then draws a card.

Concealing Curtains // Revealing Eye

Demonic Bargain

Exile the top thirteen cards of your library, then search your library for a card. Put that card into your hand, then shuffle.

Dreadfeast Demon

Flying
At the beginning of your end step, sacrifice a non-Demon creature. If you do, create a token that's a copy of this creature.

Supernatural Rescue

This spell has flash as long as you control a Spirit.
When you cast this spell, tap up to two target creatures you don't control.
Enchant creature you control
Enchanted creature gets +1/+2.

Dying to Serve

Zombie

Whenever you discard one or more cards, create a tapped 2/2 black Zombie creature token. This ability triggers only once each turn.

Graf Reaver

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, destroy target planeswalker.
At the beginning of your upkeep, this creature deals 1 damage to you.

Headless Rider

Whenever this creature or another nontoken Zombie you control dies, create a 2/2 black Zombie creature token.

Innistrad: Crimson Vow