Deploy the Gatewatch

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 (You may cast this spell any time you could cast an instant.) Emerge 7U (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) This creature has hexproof as long as it entered this turn.

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

You may cast this card from exile. When this creature becomes the target of a spell or ability an opponent controls, exile this creature.

Emerge 6G (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, create two 1/1 green Insect creature tokens.