It of the Horrid Swarm

Emerge 6B (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, target opponent loses 3 life and you gain 3 life.

Emerge 6GGG (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, creatures you control get +2/+2 and gain trample until end of turn. Trample, haste

Emerge 5BB (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, target opponent reveals their hand. You choose from it a nonland card with mana value 3 or less and a card with mana value 4 or greater. That player discards those cards.

Flash 1, Sacrifice this creature: Destroy target artifact or enchantment.

Flash Emerge 5UU (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, tap up to four target permanents.

This spell costs 1 less to cast for each card type among cards in your graveyard. When you cast this spell, you gain control of target opponent during that player's next turn. After that turn, that player takes an extra turn. Flying, trample, protection from instants

Emerge 5U (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, draw a card. Flying

When this creature enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle. Coven — 1WW: Transform this creature. Activate only if you control three or more creatures with different powers.