msem-instigator

Gain control of target creature until end of turn. Untap it. Until end of turn, it gets -1/-1 and gains haste.

When Gulchdrinker Serpent enters, detain target permanent. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

Return target permanent card from your graveyard to your hand. You gain 3 life.

Destroy target creature. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Whenever you attack, you may double target attacking creature's power. If you do, sacrifice it at the beginning of the next step.
Whenever one or more red creatures you control enter, creatures you control get +1/+0 and gain trample until end of turn.

Lifelink
{3}{W}: Mahara Enforcer gets +3/+3 until end of turn. Activate only once each turn and only if you control another Angel or Nephilim.

At the beginning of your end step, you lose 3 life unless you sacrifice a creature.

Counter target spell. If that spell is countered this way, put it on the bottom of its owner's library instead of putting it into its owner's graveyard. You may put up to three target cards from your graveyard on the bottom of your library in any order.

Tap target creature. It doesn't untap during its controllers next untap step.
Judge target creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

Tap another untapped creature you control: Knight of the Orchards gets +1/+1 until end of turn.

Enchant creature you control
When Erebos's Benefaction enters, scry 2.
Enchanted creature gets +2/+2 and has menace.

Equipped creature gets +2/+2 and has ward {2}.
Whenever a creature you control enters, if you cast it from exile, you may attach Minstrel's Armor to it.
Equip {2}

Exile target spell or creature. For as long as it remains exiled, its controller may cast that card, and it costs {2} more to cast.

Flying
Soldiers and Knights you control get +1/+1.

Mill X cards. Then you may return a creature card with mana value X or less from your graveyard to the battlefield.

At the beginning of your upkeep, choose one —
• Create a colorless artifact token named Etherium Cell with “{T}, Sacrifice this artifact: Add one mana of any color.”
• Put a +1/+1 counter on another target artifact. It becomes a 0/0 Construct artifact creature if it isn't a creature.

Whenever a player casts a creature spell, they sacrifice a creature.
Revive—{3}{B}{G}, Sacrifice a creature. ({3}{B}{G}, Sacrifice a creature, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

(Choose only one work as a sorcery to add its ability.)
When Xie'e Amphitheatre enters, search your library for a card and exile it face down, then shuffle. You may cast that card on any turn you sacrificed a permanent.
{B}: Intro: Together
At the beginning of your upkeep, you lose 1 life and create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”
{2}{B}: Finale: Alone
Whenever a Demon you control enters, each opponent loses life equal to its power and you gain that much life.

First strike (This creature deals combat damage before creatures without first strike.)
When Zephyr Rider enters, you may have another target creature you control gain first strike until end of turn.

Whenever Tortle Veteran or another Turtle you control enters, that creature explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Whenever Vindictive Pyromancer perseveres, it deals 1 damage to any other target. (A creature perseveres when it survives damage.)

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)

At the beginning of your upkeep, each player sacrifices a nonbasic land.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Another target creature you control gets +1/+1 until end of turn.
[Lore III] Search your library for a basic land card, put it onto the battlefield, then shuffle.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] You gain 1 life.
[Lore III] Target creature you control gains first strike until end of turn.