msem-instigator

Whenever you cast a legendary spell, create a 1/1 white Human creature token.
{W}{U}{B}{R}{G}: Search your library for a legendary card, reveal it, put it into your hand, then shuffle. The next legendary spell you cast this turn costs {W}{U}{B}{R}{G} less to cast.

Menace
Whenever a land enters, you may search its controller's library for up to three land cards with the same name as that card, put them into that player's graveyard, then that player shuffles.

Equipped creature gets +1/-1 and has “When this creature dies, put a fate counter on Xueyang San.”
{1}, Remove a fate counter from Xueyang San: Choose one —
• Draw a card.
• Xueyang San deals 2 damage to any target and you gain 2 life.
Equip {1}

Flying
Whenever another creature you control enters, create an Idol token.
Whenever you put a +1/+1 counter on Ya'Ling, put a +1/+1 on each other creature you control. This ability triggers only once each turn.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{4}{G}: Target creature gets +2/+2 until end of turn.

When Yamisaran Bladedancer enters, you may attach an Equipment you control to target creature you control.

When Yamisaran Guard enters, create a colorless Equipment artifact token with “Equipped creature gets +1/+1” and equip {1}.

Other enchantment creatures you control get +1/+1.
As long as you control three or more enchantment creatures, if a triggered ability of an enchantment you control would trigger, that ability triggers an additional time.

Reach
{T}: Yangzhi Cloudpiercer deals 1 damage to target player or planeswalker.

Menace
Yaran's Enforcer gets +1/+1 as long as you foretold a card this turn.
Yaran's Enforcer gets +1/+1 as long as you cast a foretold spell this turn.

{2}, Exile a land card from your graveyard: Create a token that's a copy of that land.

Siempre que ganes vidas, los Clérigos que controlas obtienen +1/+1 y ganan la habilidad de arrollar hasta el final del turno.

Flying
Whenever Yawning Crane deals combat damage to an opponent, target tapped creature that player controls doesn't untap during its controller's next untap step.

{T}, Sacrifice another creature: Return target creature card with mana value equal to 1 plus the sacrificed creature's mana value from your graveyard to the battlefield. Activate only as a sorcery.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{1}, Sacrifice a creature: Draw a card. Each opponent loses 1 life and you gain 1 life.
Whenever you sacrifice a creature, if you're in a renaissance, each opponent sacrifices a creature. This ability triggers only once each turn.

Inspired — Whenever Yenzu Disciple becomes untapped, each opponent loses 1 life and you gain 1 life.

Demon spells you cast cost {2} less to cast and an additional 2 life to cast.
Whenever you cast a Demon spell, create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”

Whenever Yenzu Mindwrencher perseveres, each opponent discards a card. (A creature perseveres when it survives damage.)

Deathtouch
Inspired — Whenever Yenzu Nightblade becomes untapped, target creature you control gets +1/+1 and gains deathtouch until end of turn.

Enchant creature
When Yenzu Puppeteering enters, draw a card.
{1}{U}: Untap enchanted creature.

{4}, {T}, Sacrifice Yenzu Ritual Vessel: Yenzu Ritual Vessel deals 4 damage to target creature or planeswalker.

{1}{G}: Create a 1/1 colorless Construct artifact creature token.
{2}{G}{G}: Target creature you control becomes 4/4. (This lasts indefinitely.)
{4}{G}{G}{G}{G}: Put four +1/+1 counters on each creature you control with power 4 or greater.

Flying, trample
Once during each of your turns, you may cast a spell from your graveyard without paying its mana cost.
When Yhzag, Alpha and Omega is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

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.)

Flying
When Yielder of Ambition enters, target creature gets +2/+2 until end of turn.
Fleeting {W} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)