msem-instigator

Creatures you control get +2/+0 and gain menace until end of turn. (They can't be blocked except by two or more creatures.)

Flying, haste
Thermal Surger can't block.
When Thermal Surger enters, you may sacrifice a land or exile a land card from your graveyard. If you do, put a +1/+1 counter on Thermal Surger.

Sacrifice Kemono-no-Oni: Return target creature card from your graveyard to your hand.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
You may play any number of lands on each of your turns.

Crossfire deals 1 damage to each creature.
Quickdraw {2}{R} (When a creature you control blocks or becomes blocked, you may cast this spell for {2}{R}.)

Trample
Whenever Forthright Wrecker deals combat damage to a player or noncreature permanent, it deals that much damage to each other planeswalker controlled by defending player and each other battle protected by defending player.

Enchant player
At the beginning of enchanted player's upkeep, their life total becomes 10.

Catalyze. (The next spell you cast this turn costs {1} less to cast.)
Fueled Flame deals damage to any target equal to the number of times you've catalyzed this turn.

{2}, {T}: Put a +1/+1 counter on target creature you control.
{2}, {T}, Sacrifice Inspiring Effigy: Put a +1/+1 counter on each creature you control.

Skylight Fortress enters tapped.
When Skylight Fortress enters, you may search your library for a card named Skylight Fortress, reveal it, put it into your hand, then shuffle.
{T}: Add {C}.

Draw two cards. Create a tapped colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Vanishing 4 (This creature enters with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Remove a time counter from Tideshift Elemental: You may tap or untap target creature.

Enchant player
Creatures attacking enchanted player get +1/+0.
If Curse of Incurable Wounds would be put into a graveyard from the battlefield, exile it instead.

Surveil 2, then draw three cards. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Trample
World Tender's power and toughness are each equal to twice the number of differently named lands you control.

At the beginning of your draw step, draw an additional card. If you control three or more artifacts, draw two additional cards instead.
At the beginning of your end step, discard your hand.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Back-Alley Vandal desecrates a permanent, put a +1/+1 counter on Back-Alley Vandal.

Flying
When Andazir Assaulter enters, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

When Collapsing Frame enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, Sacrifice Collapsing Frame: Draw a card.

Create a 4/4 red Dragon creature token with flying.
Showcase {5}{U}{R} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Untap all artifacts you control during each other player's untap step.
Tap two untapped artifacts you control: Target player mills two cards.

Flying, haste
Whenever Spawn of Hadak attacks, draw a card, then discard a card.

Sunken Cavern enters tapped unless another player controls a land that could produce {U} or {R}.
{T}: Add {U} or {R}.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

As an additional cost to cast this spell, sacrifice a noncreature permanent.
Search your library for a creature card with mana value equal to 1 plus the sacrificed permanent's mana value, put it onto the battlefield, then shuffle.