msem-instigator

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.)

{T}, Sacrifice Camahueto Calf: Return target land card from your graveyard to the battlefield.

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Champion of the Fae.

Other Warriors you control have trample.
{G}: Chratteri Valiant gets +2/+2 and gains trample until end of turn. Activate only once each turn.

Death knell — Add {G}. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
{W}{B}{G}: Trigger a death knell of target permanent you control.

{T}: Add one mana of any color.
Augmented — Whenever a nontoken creature you control enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on it.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
When Colpah Mystic enters, you may discard a card. If you do, creatures you control named Colpah Mystic get +2/+2 until end of turn.

Adorned — Commoners' Favored gets +2/+2 as long as it's equipped and/or enchanted.

When Conduit of the Conflux enters, scry 2.
{T}: Add one mana of any color.

Landfall — Whenever a land you control enters, Convoy's Companion gets +1/+1 until end of turn. If that land was a Desert, put a +1/+1 counter on it instead.

Reach
When Cordial Ticketmaster enters, put a +1/+1 counter on target creature.

When Gillo enters, reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. If it's a creature card, put it into your hand.
As long as you control five or more creatures with different names, creatures you control get +1/+1 and have trample.

{T}, Tap two other untapped creatures you control: Add two mana of any one color.

When Croakfolk Troubadour enters, draw a card.

When Curious Charter enters, it 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.)
As a permanent you control explores a land, you may put it onto the battlefield rather than into your hand.

Other creatures you control get +1/+1 as long as you control four or more lands.
{G}, Sacrifice Daisy, the Heart of Chasmek: Creatures you control with base power 1 or less gain indestructible until end of turn.

{T}, Mill a card: Add {G}.
{2}{G}{G}, Sacrifice Danithra Caller: Mill two cards, then create two 1/1 blue Tentacle creature tokens.

When Daughter of Calenfyr enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
When Daughter of Calenfyr dies, you may put a land card from your hand onto the battlefield tapped.

Deathtouch
{3}{G}: Deathcoil Cobra gains indestructible until end of turn.

{T}: Add {G}. If a -1/-1 counter was put on a creature you control this turn, add {G}{G} instead.

When Defiant Bristles dies, put a +1/+1 counter on target creature.

When Disciple of the Buried Glade leaves the battlefield, create a 3/3 green Elemental creature token.

When Doomed Woodsman dies, create a 1/1 green Faerie Druid creature token with hexproof.

When Dualglaive Acolyte enters, create a green Aura enchantment token named Calamighty attached to target creature. The token has enchant creature and “Enchanted creature gets +1/+1 and can't be blocked by creatures with power 2 or less.”