msem-instigator

Target creature you don't control fights target creature you control, then fights up to one other target creature you don't control.

Flying
Herald of Oblivion enters with X -1/-1 counters on it, where X is your life total.

Abandoned Preserve enters tapped if you control another nonbasic land.
{T}: Add {B} or {G}.

Flying
Whenever a creature you control attacks alone, choose one —
• Exile target creature with power less than that creature's power.
• Put two +1/+1 counters on that creature.
• That creature gains first strike and lifelink until end of turn. Untap it.

Enchant creature
Enchanted creature gets +2/+2.
When enchanted creature dies, return it to the battlefield under its owner's control.

Adorned — Daelish Archer has first strike as long as it's equipped and/or enchanted.

Prowess
When Rosebud Runner enters, exile the top card of your library. During your next turn, you may play that card from exile.

Creatures you control have base power 4 and gain trample until end of turn.

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
You gain 6 life. If this spell's tithe was paid, draw a card.

{T}: Add {G}. If there are three or more creature cards in your graveyard, add {G}{G} instead.

Whenever a creature enters under an opponent's control, you may have that player lose 1 life.
Unveil {2}{B}{R} ({2}{B}{R}: Transform this. Unveil only as a sorcery.)

{1}{G}: Rhudai Pathfinder gets +X/+X until end of turn, where X is the number of differently named lands you control. Activate only once each turn.

You may have Warped Physiognomist enter as a copy of any creature on the battlefield with mana value 3 or less.

Raider's Den enters tapped.
{T}: Add {R}.
{R}, {T}: Target creature you control gains menace until end of turn. Activate only as a sorcery and only if you control a red creature.

You may exert Migrating Herd as it attacks. When you do, sacrifice a land and draw a card. (An exerted creature won't untap during your next untap step.)

Enchant creature
Enchanted creature gets +2/+2.
Whenever enchanted creature attacks, create a 2/2 white Knight creature token that's tapped and attacking.

You may cast Gateblessed Explorer from your graveyard as long as you control three or more creatures.
Whenever another creature dies, each opponent loses 1 life and you gain 1 life.

Whenever Mahara Vanguard attacks, Soldiers you control get +1/+0 and gain menace until end of turn.

Bleed {2}{U} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
Put target creature on top of its owner's library.

Whenever another Hound you control enters, put a +1/+1 counter on Greypelt Initiate.

(Add a quest counter as this enters. Sacrifice after 4.)
Whenever a creature you control enters, add a quest counter.
1 — Exile target nonland permanent an opponent controls until target creature you control leaves the battlefield.
2, 3 — Each player may scry 1.
4 — Put all cards exiled with Bind the Great Evil into their owners' graveyards.

Wary Rider has first strike as long as its attacking.
Wary Rider gets +1/+0 as long as you control two or more other creatures.

Prevent all combat damage that would be dealt this turn by creatures other than Citizens and Peasants.

Exile target artifact or creature you control, then return that card to the battlefield under its owner's control. Create a 1/1 white Spirit creature token with flying.
Flashback {2}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

This spell has flash as long as you control another enchantment.
When Kernel Quarantine enters, exile all other creatures until Kernel Quarantine leaves the battlefield.