msem-instigator

Choose one or more —
• Counter target activated ability or triggered ability.
• Prevent all combat damage that would be dealt this turn.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
If you would gain life, you may put a +1/+1 counter on this creature instead.
When this creature has toughness 20 or greater, you win the game.

Haste
When Speaker of the Iris enters, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
Other creatures you control have haste.

Trample
Morph {3}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When you turn Spearhead Ophan face up, creatures you control get +2/+2 and gain trample until end of turn.

Enchant creature
When Spectral Chains enters, create two 1/1 white Spirit creature tokens with flying.
As long as you control a creature, enchanted creature can't attack or block and its activated abilities can't be activated.

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.

Flash
Flying
When Spectrum Archmage enters, return target spell to its owner's hand, then abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

Exile up to three target instant and/or sorcery cards from your graveyard. Until end of turn, you may cast cards exiled this way.
Exile Speedreading.

Counter target noncreature spell unless its controller pays {2}.

Instant and sorcery spells your opponents cast cost {1} more to cast.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card.

Whenever you cast a noncreature spell, you may pay {U}. If you do or the spell was cast from your graveyard, draw a card.

Haste
Whenever Spellslinger Elf deals combat damage to a player, draw a card, then you may cast a card from your hand with mana value 3 or less without paying its mana cost.

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Remove a +1/+1 counter from Spellsword Elite: The next noncreature spell you cast this turn costs {1} less to cast.

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

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

Spinerock Canyon enters tapped unless you control a basic land.
{T}: Add {R} or {W}.

({T}: Add {R} or {W}.)
Spiraling Canyon enters tapped unless you control a basic Mountain or a basic Plains.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {W} or {U}.

{T}: Add {C}.
{T}: Add one mana of any color among creatures you control.
{X}: Spirit Blossom Shrine becomes an X/X Spirit creature until end of turn. It's still a land. Activate only if you control a creature with power X.

Lifelink
Revive {W} ({W}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Draw two cards, then discard a card.
Whenever you cast an instant or sorcery spell, if Spirit Script is in your graveyard, you may have it become a copy of that spell until end of turn.

Whenever Spirit of Infamy attacks, post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)
Spirit of Infamy gets +2/+0 for each bounty counter on it.

Flying, lifelink
Skip your draw step.
Pay 3 life: Draw three cards. Activate only as a sorcery and only once each turn.