msem-instigator

Flying, trample
Whenever an opponent casts a noncreature spell, that player loses 5 life unless they sacrifice a creature or discard a card.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Spectral Hunter envisions a creature card, creatures you control get +1/+0 until end of turn.

This spell costs {1} less to cast for each other spell you've cast this turn.

Flying
When Sphinx of Riddles enters, secretly choose a card name. You may reveal the chosen name any time.
Whenever a spell an opponent controls with the chosen name resolves, you may draw two cards.

Trample
When Spikehorn Behemoth leaves the battlefield or phases out, draw a card.

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.)
Menace

Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Flying, lifelink
Other creatures you control have lifelink.

Vigilance, trample
At the beginning of combat on your turn, put a +1/+1 counter on target legendary creature you control.

Flying
Whenever Starborne Hellkite attacks, choose two—
• Starborne Hellkite deals 4 damage to any target.
• Destroy target artifact or land.
• Creatures you control get +2/+0 until end of turn.

Flying
Other creatures you control with flying get +2/+2.

Trample
When Stensia Cavalcade enters, create two Weapon tokens. (They're Equipment artifacts with “Equipped creature gets +1/+1” and equip {2}.)

Flying
Tap an artifact you control, a creature you control, and an enchantment you control: Return Stonecut Lammasu from your graveyard to your hand. Activate only as a sorcery.

When Stonefall Golem leaves the battlefield, destroy target permanent.

When Suburban Runebrawler enters, exile target instant or sorcery card with mana value 2 or less from your graveyard.
Landfall — Once each turn, when a land you control enters, you may cast a copy of the exiled card without paying its mana cost.

Trample, haste
Whenever Sugon, Destruction's Fist deals combat damage to a player, return it to its owner's hand unless you have Sugon deal 5 damage to you.

Vigilance, reach
Noncreature spells cost {2} more to cast.
Cycling {2} ({2}, Discard this card: Draw a card.)

Whenever a land you control enters, if you haven't had a land become a copy this way this turn, you may have that land enter as a copy of any nonland permanent on the battlefield.

Whenever Sunken One attacks, target creature defending player controls gets -13/-0 until end of turn.
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

You may sacrifice three Treasures rather than pay this spell's mana cost.
Flying, trample, haste

Menace, reach
When Surfacing Horripede enters, surveil 2.

Reach
Whenever another creature enters, untap Sylvan Subversive.

Flying
When Syrina, the Dragon Queen enters, gain control of target nonland permanent for as long as you control Syrina, the Dragon Queen.
{2}{U}: Exile Syrina, the Dragon Queen. Return her to the battlefield at the beginning of the next end step.

Flash
TT-23 Aegis can't attack or block unless you have six or more cards in hand.
At the beginning of your end step, if you didn't cast a spell this turn, draw a card.

Reach, trample
Tallowkeep enters with two wax counters on it.
Whenever Tallowkeep attacks, remove a wax counter from it. Then if Tallowkeep has no wax counters on it, sacrifice it.
Whenever another artifact you control enters, put a wax counter on Tallowkeep.