msem-instigator

Trample
At the beginning of your upkeep, return another creature you control to its owner's hand.

Target creature gets +1/+0 and gains indestructible until end of turn. Draw a card if you control an Angel, Demon, Faerie or Spirit.

Whenever a land you control enters, amass Soldiers 1. If that land is a Satrapy, amass Soldiers 2 instead. (To amass Soldiers 2, put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create a 0/0 black Soldier Army creature token first.)

({T}: Add {U} or {B}.)
As Ruptured Grotto enters, you may pay {1}. If you don't, Ruptured Grotto enters tapped.

Whenever a creature you control becomes the target of a spell or ability, counter it unless its controller pays {1}. Whenever they do, put a +1/+1 counter on Brushcover Elf. (This includes your spells and abilities.)

{1}{W}: Untap Steadfast Infantry.

Reveal cards from the top of your library until three creature and/or land cards are revealed this way. Put all creature and/or land cards revealed this way into your hand and the rest into your graveyard.

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.
{3}{W}{U}: Tap target creature and put a +1/+1 counter on Solitary Guardian.

Advance {1}{R} (Cast this for {1}{R} to advance it as it enters. {1}{R}: Advance this as a sorcery.)
Whenever Blitz Breaker advances, its power becomes equal to the amount of noncombat damage that's been dealt to your opponents this turn. (This effect lasts indefinitely.)

Whenever one or more creatures attack you or a planeswalker you control, reveal the top card of your library, then put a -1/-1 counter on each attacking creature with the same mana value as the revealed card.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | When you next cast an instant or sorcery spell this turn, copy it. You may choose new targets for the copy.
3 | When you cast your next creature spell this turn, copy it.

Haste
When Volt Vermin enters, it deals damage to target player or planeswalker equal to the number of creatures with flash and/or haste you control.

{1}{B}, Sacrifice another creature, Discard two cards: Search your library for a card, put that card into your hand, then shuffle.

Flying

When Militia Commander enters, create a 1/1 white Peasant creature token.
Other Citizens and Peasants you control get +1/+1.

When Lunar Vigil enters, draw a card, then scry 2.
If you would draw one or more cards, you may instead put a night counter on Lunar Vigil and draw that many cards minus one.
Sacrifice Lunar Vigil: Target player draws a card and adds {R} for each night counter on it.

Enchant creature
Enchanted creature can't attack or block unless its controller pays {3}.
Activated abilities of enchanted creature cost {3} more to activate.

Once each turn, when you activate an ability of a permanent you control that isn't a mana ability, you may exile that permanent. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step.

{G}, {T}: Create a 1/1 green Elf creature token.
{3}{G}{G}, {T}: Create a 3/3 green Beast creature token.

Target creature deals damage equal to its power to its controller.

When Warden of the Archives enters, if you cast it, tap up to four target permanents.

Whenever a creature you control dies, put a rot counter on Fester Swarm and you gain 1 life.
{B}{G}, Remove two or more rot counters from Fester Swarm: Create a 1/1 green Insect creature token, then put a +1/+1 counter on it for each rot counter removed this way.

Flash
When Ceaseless Valiant enters, another target permanent gains indestructible until end of turn.
Recite {1}{W} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)