msem-instigator

Trample
Whenever you cycle Long-Term Method Actor or it attacks, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
Basic landcycling {1}{G} ({1}{G}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

When Lupine Prowler enters, you may sacrifice another creature. If you do, draw a card and you gain 2 life.
Whenever another creature you control dies, put a +1/+1 counter on Lupine Prowler.

When Machi's Assistants enters or you gain life, you may mill four cards. When you do, you may return a permanent card from your graveyard to your hand. This ability triggers no more than four times each turn.

Flash

You may exert Migrating Herd as it attacks. When you do, sacrifice a land and draw a card. (An exerted creature won't untap during your next untap step.)

Mindhunter Grizzly can't attack or block unless you scried this turn.
{5}{U}: Scry 1.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

When Nettlehowler enters, exile up to one target card from a graveyard.
If a creature dealt damage by Nettlehowler this turn would die, exile it instead.

Ward {3}
Whenever Operative SPORTY attacks or you cast a blue or black spell, put a +1/+1 counter on Operative SPORTY.

Hexproof
Spells you cast cost {1} less to cast for each creature you control that shares a creature type with that spell.

Whenever Pineblight Caribou enters or attacks, you may have it consume a land. If you do, draw a card and you gain 2 life. (To consume a land, sacrifice a land or exile a land card from your graveyard.)

Reach
You may cast a copy of Primal Echo from your graveyard by exiling it and paying {2} in addition to its other costs. (The copy enters as a token.)

Trample
Whenever Quakestep Behemoth or another creature you control enters, put X +1/+1 counters on each creature you control, where X is the entering creature's power.

Whenever another nontoken creature you control dies, you may return it to the battlefield tapped face down under its owner's control. It's a Forest land.
{4}{G}, Return a land you control to its owner's hand: Create a 3/3 green Wurm creature token. Activate only as a sorcery.

Runewart Hog has hexproof as long as it has a +1/+1 counter on it.

Indestructible
Lands you control have “{T}: Add {G}{G}.”
{5}{G}{G}: Double the power and toughness of each creature you control until end of turn.

Trample
Whenever Saghira, Divinity's Usurper attacks, you may pay {1}{G}. If you do, destroy target artifact, enchantment, or creature with flying.

Vigilance
{1}{G}{G}: Sahalia Dragoons gets +4/+4 until end of turn. Activate only once each turn.

Poisonous 4 (Whenever this creature deals combat damage to a player, that player gets four poison counters.)
At the beginning of combat on each of your turns, if an opponent is poisoned, creatures you control gain trample until end of turn.

When Silverhorn Tactician enters, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Adorned — As long as Silverwork Champion is equipped and/or enchanted, it gets +2/+2 and has trample.

Menagerie — {1}{G}: Slipsand Hornshell gains indestructible until end of turn. Tap it. Activate only if there are five or more creature types among creatures you control.

Snowy Misthorn can block creatures with distorted as though it was tapped.

Trample
When Spawn of Qiyan enters, distribute four +1/+1 counters among any number of target creatures you control.
{2}{G}: Put Spawn of Qiyan from your graveyard into your library second from the top.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Renown 3 (When this creature deals combat damage to a player, if it isn't renowned, put three +1/+1 counters on it and it becomes renowned.)