msem-instigator

Whenever you play a land, you may put a land card from your hand onto the battlefield tapped.

Scry 1. Draw a card. Scry 1.

When Greedy Rapscallions enters, mill three cards. If two or more nonland cards were put into your graveyard this way, put a +1/+1 counter on Greedy Rapscallions.

Target creature gains indestructible until end of turn.
Fuse (You may cast one or both halves of this card from your hand.)

Whenever an opponent activates an ability that isn't a mana ability, amass Soldiers 1 unless its controller pays {2}. (To amass Soldiers 1, put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create a 0/0 black Soldier Army creature token first.)

Choose one —
• Destroy target artifact.
• Crushing Grip deals 2 damage to any target.

Deathtouch
Whenever you cast a spell, you may pay 2 life. If you do, that spell gains deathtouch. (If it becomes a permanent, it keeps deathtouch indefinitely.)

Prowess
Whenever you cast an instant or sorcery spell, if its mana value is less than or equal to Dwarven Twinslinger's power, copy that spell. You may choose new targets for the copy.

Mill three cards. Pyromancer's Fury deals damage to any target equal to the number of instant and sorcery cards in your graveyard.

Tinyvale Treetops enters tapped unless you played it from exile.
{T}: Add {G} or {W}.

Return target creature card from your graveyard to your hand.

Whenever you cast an enchantment spell, you may put target creature on the bottom of its owner's library.

Enchant creature
When Eternal Banishment enters, put a +1/+1 counter on enchanted creature.
Remove a +1/+1 counter from enchanted creature: Exile target creature an opponent controls until Eternal Banishment leaves the battlefield. Activate only as a sorcery.

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.)
Whenever this creature attacks, if it's merged with another card or token, it deals 2 damage to target player or planeswalker.

When Royal Retriever enters or when a creature you control scavenges it, you may discard a card. If you do, draw a card.
Scavenge {R} ({R}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Whenever you cast an instant or sorcery spell, tap target creature an opponent controls.

This spell costs {2} less to cast if its target has the same name as a card in a graveyard.
Scoff deals 3 damage to any target.

Swiftstep Cliffdweller has haste as long as you control another Goblin.

Until end of turn, target creature you control gets +1/+1 and target creature an opponent controls gets -1/-1.

Creatures you control get +2/+0 until end of turn.
Metamorph {1}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

{W}, {T}: Remove target creature you control from combat.

Codex — Unraveling; Unraveling; Unrelenting; Unrelenting; Mindrip; Swipe Secrets. (As this enters, conjure its contents into a shuffled face-up additional library.)
Flash
When Mei's Collection enters, draw a card from its codex.

Target opponent reveals their hand. You choose a card from it. Exile that card. If a land card is exiled this way, its owner may conjure a card named Plains, Island, Swamp, Mountain, or Forest on top of their library.

Vanguard — Whenever a creature you control attacks alone, that creature gets +3/+0 until end of turn.