msem-instigator

If a counter would be put on another creature you control, you may put an additional counter of that kind on Kinsang Spiritualist.
Scavenge {4}{G} ({4}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Whenever an opponent casts a noncreature spell, put a +1/+1 counter on target creature you control.

When Landbirth Elemental enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever a Role becomes attached to Lead Athlete or you cast a spell that targets it, put a +1/+1 counter on Lead Athlete.

When Library Infiltrator enters, target creature can't be blocked by creatures with lesser power this turn.
Whenever one or more creatures you control deal combat damage to a player or planeswalker, draw a card.

As Living Sandstorm enters, choose predator or prey.
Whenever Living Sandstorm attacks,
• Predator — It gets +1/+1 until end of turn.
• Prey — Scry 2.

Trample
Whenever a land you control becomes tapped, Loamwrecker gets +1/+1 until end of turn.

Defender, trample
Whenever you lose life, Loyal Watchdog may attack as though it didn't have defender until the beginning of your next end step.

At the beginning of each combat, if you control a creature with flying, Magnific Wilderkin gets +1/+1 and gains flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Poisonous 3 (Whenever this creature deals combat damage to a player, that player gets three poison counters.)
At the beginning of your upkeep, if an opponent is poisoned, you may have Mautakesh Strangler fight target creature you don't control.

As long as you control another white creature, Mavisa's Familar has lifelink. The same is true for blue and flying, black and deathtouch, and red and trample.

Survivors you control get +3/+3.

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Mold Shambler enters, if it was kicked, destroy target noncreature permanent.

When Moss Dweller enters, put a +1/+1 counter on another target creature.

At the beginning of your upkeep, germinate. Then if creatures you control have total power 10 or greater, transform Mushroom Merchant. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Reverberate {2}{G} (When you cast this spell, copy it if you paid its reverberate cost. The copy becomes a permanent when it resolves.)
Mystical Echo gets +1/+1 for each other Reflection you control.
Whenever you discard a card, Reflections you control gain trample until end of turn.

{T}: Mystical Elk becomes a copy of target creature card in your graveyard. Activate only as a sorcery. (It loses this ability.)

Reach
Whenever Nanowrought Vanguard attacks, put a +1/+1 counter on each enchantment creature you control.

Vigilance
Mountaincycling {1}, plainscycling {1} ({1}, Discard this card: Search your libary for a Mountain or Plains card, reveal it, put it into your hand, then shuffle.)

When Night Shepherd enters, return a creature you control to its owner's hand.

Trample
Ride {3}{G} ({3}{G}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Target creature you control can't be blocked by creatures with power 2 or less this turn.
[Lore III] Draw a card.

Trample
Whenever you attack with another creature with power 4 or greater, put a +1/+1 counter on OH-14 Diamond.

Whenever one or more artifacts you control enter, put a +1/+1 counter on Octopus Shiny-Grabber and you gain 1 life.