msem-instigator

Whenever a creature with flying attacks you, gain control of that creature at end of combat.

Enchant creature
Whenever enchanted creature attacks, it gets +3/+3 and gains trample until end of turn.

Destroy target creature an opponent controls, then that player sacrifices a creature.

Whenever Murkriver Trawler attacks, until end of turn, target Rogue gains “Whenever this creature deals combat damage to a player, draw a card.”

Return target creature to its owner's hand. You may shuffle up to four target cards from your graveyard into your library.

Target creature gets -1/-1 until end of turn. Germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Trample
Whenever Muse of Summer Revelry enters or you cast a spell with power 4 or greater, choose one —
• You gain 3 life.
• Create a 2/2 green Wolf creature token.
• Draw a card.

Draw two cards.
Crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase. For each planeswalker you control, you may activate its loyalty abilities an additional time this turn.

At the beginning of your upkeep, germinate. Then if creatures you control have total power 10 or greater, transform Mushroom Merchant. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Counter target enchantment, instant, or sorcery spell. (Then exile this card. You may cast the creature later from exile.)

Put a +1/+1 counter on up to one target creature. (Then exile this card. You may play the land later from exile.)

Create two 1/1 white Soldier creature tokens. Prevent all damage that would be dealt to them this turn.

You may have Mutalithic Golem enter as a copy of any land on the battlefield, except it's an artifact in addition to its other types.

First strike
When Mutilated Warrior enters, you may have it deal damage to each player equal to the number of Warriors you control.

Whenever a creature you control dies, destroy target creature you don't control.

Menace
Other attacking Hounds you control get +2/+0.

Reveal cards from the top of your library until you reveal a creature card and a land card. Put those cards into your hand and the rest on the bottom of your library in a random order.
Concord — If there are four or more card types among permanents you control, create two Treasure tokens.

Equipped creature gets +2/+2.
Concord — Whenever equipped creature attacks, if there are four or more card types among permanents you control, create a 3/3 red Shark enchantment creature token that's tapped and attacking. Exile that token at the beginning of the next end step.
Equip {1}

[+1]: Create a tapped colorless artifact token named Conch Shell with “{T}: Add one mana of any color. Spend this mana only to cast permanent spells.”
[–1]: Reveal the top X cards of your library, where X is the number of card types among permanents you control. Put a permanent card from among them into your hand and the rest into your graveyard.
[–3]: Create two 3/3 red Shark enchantment creature tokens.

Whenever Mysteries of Life enters or you create a token, choose one that hasn't been chosen this turn —
• You gain 2 life.
• Draw a card, then discard a card.
• You may tap or untap target permanent.

Whenever a card is put into a graveyard this turn, you may put it on the bottom of its owner's library.
Draw a card.

Return a permanent you control to its owner's hand.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

{X}, Exile Mysterious Coffer: Return all nonland permanents with mana value X or less to their owner's hands.

Choose one —
• Return target artifact or enchantment card from your graveyard to your hand.
• Return target creature card with mana value 2 or less from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)