msem-instigator

Whenever this creature enters or attacks, each player discards a card. If one or more land cards were discarded this way, this creature gains deathtouch until end of turn.
At the beginning of each opponent's end step, if that player didn't cast a spell this turn, that player loses 2 life and you gain 2 life.

Creatures you control get +1/+1 until end of turn. Merfolk you control get an additional +1/+1 until end of turn.

At the beginning of combat on your turn, target creature you control gets +1/+0 until end of turn. If you cast two or more spells this turn, it also gains haste and trample until end of turn. If you cast three or more spells this turn, it gets an additional +2/+0 until end of turn.

When Mouthpiece of Yhzag enters, you may have target opponent create a tapped 1/1 colorless Human creature token.
Whenever Mouthpiece of Yhzag attacks, gain control of target Human creature you don't control with mana value 3 or less until end of turn. Tap it. It's attacking.

Whenever two or more creatures an opponent controls attack, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Enchanted creatures you control get +0/+2.

Target opponent reveals their hand. You choose an instant or sorcery card from it or a card from their graveyard. Exile that card.

Survivors you control have double strike.

Vigilance
Whenever you cast an artifact spell, put a +1/+1 counter on Relitian Sentry.
Equipped creatures you control get +1/+1 and have first strike.

Whenever Orria Mirrorpelt becomes the target of a spell, exile that spell. If Orria Mirrorpelt was its only target, copy it for each other creature target player controls. Each copy targets a different one of those creatures.

When Troubled Heir dies, create a tapped Plains token.

Flying
Spells you cast from anywhere other than your hand cost {2} less to cast.
Spells your opponents cast from anywhere other than their hand cost {2} more to cast.

Whenever Knight of the Hawk deals combat damage to a player, you may sacrifice it. If you do, search your library for a red legendary creature card, reveal it, put it into your hand, then shuffle.

Menagerie — This spell costs {2} less to cast if there are five or more creature types among creatures you control.
Destroy target creature with power or toughness 4 or greater.

Archive 5, archive 5, archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library three times. Sacrifice this after the archived libraries are empty.)
At the beginning of your upkeep, exile the top card of each of your libraries. For each card exiled this way, you may play it without paying its mana cost.

Indestructible
You have no maximum hand size.
Whenever an opponent draws a card, you draw a card.
If you would lose the game other than for having 0 or less life, you win the game instead. (Another player winning the game does not cause you to lose the game.)

The Pillaging of Kaneh deals X damage to each creature and each planeswalker, where X is the number of Satrapies you control.

When R-12 Lone Digger enters, it deals 3 damage to target player or planeswalker.

Choose one —
• Target creature gets +3/+3 until end of turn.
• Target creature blocks this turn if able.
• Scry 1, then draw a card.

Yi Cang, Thief of Blessings enters with a +1/+1 counter on them.
{1}: Yi Cang becomes a copy of target creature in their pack, except their name is Yi Cang, Thief of Blessings, they're legendary in addition to their other types, and they have this ability. (Two or more creatures you control with equal power are in a pack.)

As Straw Simulacrum enters, choose a creature type.
Straw Simulacrum is the chosen creature type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Destroy target creature. If an opponent lost life this turn, that creature's controller mills five cards.

Whenever Akoum Pathfinder attacks, create a 1/1 red Goblin creature token.
Other Goblins you control get +1/+0 and have haste.

Trample
When Leyran Alpha enters, create two 2/2 green Wolf creature tokens with haste.
Whenever a creature you control deals damage to an opponent, put a +1/+1 counter on that creature.

Unending Slime enters with X +1/+1 counters on it.
{2}{G}{G}{G}: Return Unending Slime from your graveyard to your hand.

{B}{G}{U}: Mother Roo gets +2/+2 and gains flying until end of turn.