msem-instigator

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Counter target spell unless its controller pays {1}.

({T}: Add {U}.)
Aerie's Pillar enters the battlefield tapped.
Flying
{2}{U}{U}: Aerie's Pillar becomes a creature in addition to its other types until end of turn.

[+1]: Aiel Tazan deals 2 damage to any target. Then she deals 2 damage to herself unless you have her deal 2 damage to you.
[–3]: Creatures you control get +2/+0 and gain haste until end of turn.
[–X]: Create an X/1 red Elemental creature token with haste and trample. Exile that token at the beginning of the next end step. If X is 6 or more, it gains double strike.

As Amber Hills enters the battlefield, you may pay 2 life. If you don't, Amber Hills enters the battlefield tapped.
{T}, Sacrifice Amber Hills: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

When Ancestral Council enters the battlefield, search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Counter target spell if it shares a color with mana spent to cast Antimagic.

({T}: Add {W} or {B}.)
Whenever Arctic Mine becomes tapped, you lose 1 life unless you control two or more basic lands.

Haste
Whenever Banished Companion attacks, it deals 2 damage to you.

Choose two —
• Target player creates two 2/2 white Knight creature tokens with vigilance.
• Destroy target creature with power 4 or greater.
• Target player gains hexproof until end of turn.
• Return target nonland permanent you don't control to its owner's hand.

Choose one —
• Target creature gets +2/-1 until end of turn.
• Basat Charm deals 3 damage to target player or planeswalker.

Create an X/X green and blue Plant creature token, where X is the number of differently named lands you control.

Destroy target artifact.
Reprise {R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

Flash
When Cane Dancer enters the battlefield, you may cast target blue instant or sorcery card with mana value 2 from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Haste
Caulte Axeslinger gets +2/+2 as long as any opponent lost exactly 3 life this turn.

Abound. Then search your library for a creature, instant, or sorcery card, reveal it, put it into your hand, then shuffle. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

When Coralight Champion enters the battlefield, create a white Aura enchantment token named Hila's Favor attached to target creature. The token has enchant creature and “Enchanted creature has double strike as long as there's another Aura attached to it. Otherwise, it has first strike.”

({T}: Add {B}.)
Corpsebed enters the battlefield tapped.
When Corpsebed enters the battlefield, exile up to two target cards from graveyards.

Glitch {1}
Target opponent reveals their hand. You choose a [noncreature,] nonland card [with mana value 3 or less] from among them. That player discards that card.

Converge — Counter target spell unless its controller pays {1} for each color of mana spent to cast Cosmic Sinkhole.

Cradle of Corruption enters the battlefield tapped.
Whenever a creature dies, put a creation counter on Cradle of Corruption.
{T}, Remove ten creation counters from Cradle of Corruption and sacrifice it: Put up to two target creature cards from graveyards onto to battlefield under your control. Activate only as a sorcery.

({T}: Add {B} or {R}.)
Whenever Crumbling Precipice becomes tapped, you lose 1 life unless you control two or more basic lands.

({T}: Add {U} or {R}.)
Whenever Crystal Cavern becomes tapped, you lose 1 life unless you control two or more basic lands.

Put three +1/+1 counters on target land. It becomes a 0/0 colorless Elemental creature with haste that's still a land.
Orchestrate—Sacrifice a land. (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, cast this from exile without paying its mana cost.)

Counter target spell with mana value 3 or less.

Counter target monocolored spell. Its controller loses 2 life.