msem-instigator

Reach
Whenever one or more creatures with flying attack, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Harpstring Ranger gets +2/+2 until end of turn. Untap it.

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Enchant land
Whenever enchanted land is tapped for mana, its controller adds one mana of any color.

At the beginning of your upkeep, create a 1/1 green Saproling creature token.
Whenever a creature you control dies, put a +1/+1 counter on Heart of Spores.
{X}{G}: Move X +1/+1 counters from Heart of Spores onto target creature. Activate only as a sorcery.

Target permanent you control gains hexproof until end of turn. If that permanent is a creature, it also gets +1/+1 until end of turn.

Creature spells you cast cost {1} less to cast.

Put a +1/+1 counter on up to one target creature. Untap it. You gain 3 life.

Whenever Hedge Dashers attacks, if you control a permanent with a counter on it, Hedge Dashers gets +1/+1 and gains trample until end of turn.

{2}{G}: Exile up to three cards from graveyards. Autocrat X, where X is the number of cards exiled this way. (If you don't control an autocrat, put X +1/+1 counters on this. It becomes an autocrat until it has no +1/+1 counters on it.)
Whenever Hegemony Monarch attacks, you may exile target card from a graveyard. If you do, untap it and it gains trample until end of turn.

Trample
Whenever Heir to the Old Bonds becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.

Trample
Resolute — At the beginning of combat on your turn, if Helicos Gargantua's power is greater than its base power, double its power until end of turn.

This spell costs {X} less to cast, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Trample

Whenever Herald of Earth deals combat damage to a player, draw a card.
Whenever you draw a card, put a +1/+1 counter on Herald of Earth.

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.

{T}: Add one mana of any color. When you spend this mana to cast a spell with mana value 5 or greater, put two +1/+1 counters on Herald of the New Divinity.

Put a +1/+1 counter on target creature you control. Prevent all damage that would be dealt to that creature this turn.

(Transform this if it's not attached to a creature. Pay {4}{G} as a sorcery to unattach it.)
Enchant creature you control
Herdstrider's rider gets +1/+1 for each land you control and has trample.
Whenever Herdstrider's rider attacks, create an X/X green Elephant creature token with trample that's tapped and attacking, where X is that creature's power. Exile that token at the end of combat.

For each color among nontoken permanents you control, add one mana of that color.

Target player sacrifices any number of lands. That player searches their library for up to that many land cards, puts them onto the battlefield tapped, then shuffles.
Fabled {5}{G}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

You may have Hero of Shengin Province assign its combat damage as though it weren't blocked.
{2}{G}: Until end of turn, you may have creatures you control assign combat damage as though they weren't blocked. Activate only if Hero of Shengin Province is in your graveyard.

Vigilance
Concord — {G}: Hero of the Stained Blade gets +2/+2 and gains trample until end of turn. Activate only if there are four or more card types among permanents you control and only once each turn.

Search your library for a basic land card and put it onto the battlefield, then shuffle. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flash
Whenever another permanent dies, put a +1/+1 counter on Heyu.
{1}{G}: Heyu becomes a colorless Island land until end of turn.

At the beginning of your upkeep, put a +1/+1 counter on Heyu, Immortal Hunter.
Whenever Heyu becomes the target of a spell or ability an opponent controls, counter it if Heyu has the greatest power among creatures on the battlefield.