msem-instigator

Whenever Solvent Tide attacks, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Menace
Inspired — Whenever Soul Engulfer becomes untapped, each opponent loses 4 life.

Trample, haste
When Soul of the Mountain enters, if it isn't a token, for each two Mountains you control, create a token that's a copy of it.

When Soul of the Sands enters, choose one —
• You gain 4 life.
• If you gained life this turn, 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.)
Haste

Flying
When Soulstone Redeemer dies, you may exile target creature. If you do, you gain life equal to its toughness.

Prowess, trample
During your turn, each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost plus “Pay X life, where X is this card's mana value.”

Flying, haste
Whenever you cast an instant or sorcery spell, Sovereign of Old Jidai gets +1/+0 until end of turn.

{1}{U}: Return Sparkling Jackalope and target creature to their owner's hands.
{5}{U}{U}: Sparkling Jackalope gets +4/+4 and gains flying until end of turn.

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

Trample
When Spawn of Qiyan enters, distribute four +1/+1 counters among any number of target creatures you control.
{2}{G}: Put Spawn of Qiyan from your graveyard into your library second from the top.

Menace (This creature can't be blocked except by two or more creatures.)
When Spawn of Shadows enters, each player loses 4 life.

Menace
Whenever you cast a cryptic spell, you may return target creature card from your graveyard to your hand. (Artifacts, enchantments and modal spells are cryptic.)

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.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{5}: Each opponent sacrifices a nonland permanent.

Flying
Whenever Spellgorger Elemental attacks, discard a card at random. If an instant or sorcery card is discarded this way, Spellgorger Elemental deals 3 damage to any target. Otherwise, draw a card.

Flying, prowess
When Spellwarden Sphinx enters, tap up to three nonland permanents. Those permanents don't untap during their controllers' next untap step.

Flying, prowess
When Sphinx Mentor enters or dies, draw a card.

Flying
If a nonland permanent an opponent controls would be returned to its owner's hand, instead gain control of it for as long as you control Sphinx Paramount.

Flying
When Sphinx of Ill Omens enters, return target permanent to its owner's hand.
Discard a card: Target creature or player gains hexproof until end of turn.

Flying, ward {3}
Whenever Sphinx of Myriad Futures attacks, look at the top three cards of your library and reveal one of them. The defending player may have you put the revealed card into your hand. If they don't, put the other two cards into your hand. Then put the remaining cards into your graveyard.

Flying
{X}{U}: Gain control of target nonland permanent with mana value X until Sphinx of Supremacy leaves the battlefield. Activate only as a sorcery.

Reach (This creature can block creatures with flying.)
When Spider Broodmother dies, create two 1/2 green Spider creature tokens with reach. (This creature can block creatures with flying.)

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