msem-instigator

At the beginning of your upkeep, you may reveal a creature card from your hand. If you do, create a token that's a copy of it, except it's 1/1 and is an artifact in addition to its other types.

Enchant land
When Unexplored Regions enters, draw a card.
Enchanted land is an artifact in addition to its other types and has “{T}: Add one mana of any color.”

{G}{G}, {T}: Create a token that's a copy of target creature you control that entered this turn, except it's an artifact in addition to its other types.

Whenever a land you control enters, create two 1/1 colorless Construct artifact creature tokens.
{4}{G}{G}: Put a +1/+1 counter on each artifact creature you control.

As long as you control four or more lands, Seeker of Untouched Beauty gets +2/+2 and has trample.
When Seeker of Untouched Beauty dies, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Whenever Reclamation Grovesculptor enters or attacks, put a growth counter on target noncreature permanent. It becomes a colorless Forest land and loses all other card types and land types.

Ravenous Hydra enters with X +1/+1 counters on it.
Whenever Ravenous Hydra deals combat damage, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)

Whenever you tap a land for mana, add an additional one mana of any color.
{8}{G}{G}: Creatures you control get +2/+2 and gain trample until end of turn.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever Primal Ruffian attacks, if it has a +1/+1 counter on it, other creatures you control get +1/+1 until end of turn. (If it had no counters on it when it attacked, this ability does not trigger.)

When Powercell Engineer enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”

When Powercell Cultivator enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”
Artifacts you control have “{T}: Add one mana of any color.”

Oldgrove Nurturer enters with a +1/+1 counter on it.
{G}, Remove a +1/+1 counter from a creature you control: Create a 1/1 colorless Construct artifact creature token.

When Malicious Growth enters and at the beginning of your upkeep, put two +1/+1 counters on target land you control.
{1}{G}: Target land you control becomes a 0/0 Elemental creature with haste and vigilance until end of turn. It's still a land.

Return target card from your graveyard to your hand.

Reach
When Kindly Greatwood enters, you gain 5 life and draw a card.

If one or more counters would be put on another permanent you control, put that many counters plus one on that permanent instead.
[+1]: Choose up to one target creature you control. When that creature deals combat damage to a player this turn, draw a card.
[–2]: Choose up to two target creatures. Put a +1/+1 counter on each of them.

Target creature you control gets +X/+X until end of turn. It fights target creature you don't control.

Trample
At the beginning of your end step, if there are two or more +1/+1 counters among creatures you control, return Herald of Might from your graveyard to the battlefield.

You may put a creature or land card from your hand onto the battlefield. Then each opponent may put a permanent card from their hand onto the battlefield. If one does, you may repeat this process.

When Flamboyant Inventor enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”
At the beginning of each combat, you may have Powercells you control become 2/2 Construct creatures with vigilance in addition to their other types until end of turn.

Whenever The Feller of Greatwoods enters or attacks, you may sacrifice two noncreature permanents. For each permanent sacrificed this way, reveal the top five cards of your library. You may put a creature card from among them onto the battlefield and the rest into your graveyard.

{T}: Add {G}.
{B/G}, {T}: Exile target card from a graveyard. If that card is a creature card, put a +1/+1 counter on Dovon, Verdant Experimenter and you gain 1 life.

When Backwoods Cultivator enters, put a +1/+1 counter on target creature you control.
When Backwoods Cultivator dies, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)

When Ancient of the Glade enters, put a +1/+1 counter on each other creature you control.
{2}, Remove a +1/+1 counter from a creature you control: That creature gains indestructible until end of turn.