msem-instigator

When The Marrow Lord enters, search your library for a card with arise, put that card into your graveyard, then shuffle.
Whenever you activate an ability of a card in your graveyard or a creature you control enters from a graveyard, this creature deals 1 damage to any target.

Equipped creature gets +2/+2.
Whenever equipped creature attacks, the next time an instant or sorcery source you control would deal damage to a creature, player, or planeswalker this turn, it deals that much damage plus 2 instead.
Equip {2}

Oathbreaker Orc attacks each combat if able.
Whenever Oathbreaker Orc attacks, it deals 2 damage to defending player unless that player sacrifices a permanent.

Rapport — Whenever Herald of the Hunt and at least one other creature you control become tapped, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)

Flash
Blind Blackguard can't block.
When Blind Blackguard enters, target player draws a card, then reveals their hand. You choose a nonland card from that player's hand, then that player puts the chosen card on the bottom of their library.

Put a +1/+1 counter on up to one target creature.
Draw a card.

When Ideologize enters, exile target creature an opponent controls and each other permanent with the same name that player controls. When Ideologize is no longer on the battlefield, return a card exiled with it to the battlefield under its owner's control.

Rei, the Supplanter gets +1/+1 for each Forest you control.
At the beginning of each player's end step, if that player didn't play a land this turn, create a Forest token.

{T}, Pay 1 life: Add {B}.
{T}, Pay 1 life, Sacrifice Murky Peat: Search your library for a Swamp card, put it onto the battlefield tapped, then shuffle.

Deathtouch
Menagerie — When Venomfrill Familiar enters, if there are five or more creature types among creatures you control, you may destroy target creature or planeswalker.

Enchant creature
Enchanted creature gets +3/+2 and attacks each combat if able.

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

Exile all creature cards from target player's graveyard. For each creature card exiled this way, search that player's library for any number of cards with the same name as that card and exile them. Then that player shuffles.

Flying, haste
{2}{B}{R}: Return Edarna's Augurling from your graveyard to the battlefield. Return it to your hand at the beginning of the next end step. Activate only as a sorcery.

Palace Hall enters tapped.
When Palace Hall enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {G} or {W}.

{T}: Add one mana of any color.
Paranoia {G} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Dominance — At the beginning of combat on your turn, if you control the creature with the greatest power or tied for the greatest power, you may pay {R}. If you do, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.

As an additional cost to cast this spell, tap any number of untapped storied permanents you control.
Return X target creatures to their owner's hand, where X is one plus the number of permanents tapped this way.

Whenever H.S.S. Demeter becomes blocked by a creature, gain control of that creature.
Whenever H.S.S. Demeter deals combat damage to a player, draw two cards.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Whenever you cast another creature spell, create a 1/1 green and white Elk Spirit creature token.
As long as you control five or more Elk, creatures you control get +3/+3 and have trample.

Choose two or four —
• Search your library for a Demon card, reveal it, put it into your hand, then shuffle. You lose life equal to its mana value.
• Sacrifice a creature. If you do, draw two cards.
• Each opponent loses 2 life and you gain 2 life.
• Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

({T}: Add {U} or {R}.)
Frostfire Geysers enters tapped unless you control a basic Island or a basic Mountain.

Enchant creature
When Erase Identity enters, tap enchanted creature.
Enchanted creature loses all abilities.
Enchanted creature doesn't untap during its controller's untap step.