msem-instigator

Whenever Heedless Astronaut attacks, it gets +2/+0 and gains indestructible until end of turn.

Trample, haste
Herald of Untold Riches gets +1/+1 for each color among other spells you've cast this turn.

Heretic's Home enters tapped.
{T}: Add {R} or {G}.
When Heretic's Home enters, you may put a loyalty counter on a planeswalker you control.

({T}: Add {R} or {G}.)
Highland Vale enters tapped.

Wanderlust — Whenever Highwild Survivalist attacks, add {R} or {G}. If you control four or more differently named lands, add {R}{G} instead. Until end of turn, you don't lose mana added this way as steps and phases end.

If a permanent with spirited entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Trample
Harmony — Put a +1/+1 counter on target Warrior you control. You gain 1 life.
Whenever one or more Warriors you control deal combat damage to a player, harmonize. (Trigger up to one harmony of a permanent you control.)

Hymn of Fury deals 1 damage to each creature, then each creature you control gains haste and double strike until end of turn.

Each nontoken land you control has all activated abilities of each other land on the battlefield.
When Idyll leaves the battlefield, until the end of your next turn, you gain “Each nontoken land you control has all activated abilities of each other land on the battlefield.”

Haste
When Inciting Bard enters, other creatures you control get +1/+0 and gain haste until end of turn.

{T}, Sacrifice a land: Destroy target land.

Until end of turn, gain control of target creature and it gains haste. Untap it.
Fuse (You may cast one or both halves of this card from your hand.)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Put a +1/+1 counter on target creature you control.
III — Double the number of counters on target creature you control.
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When Into the Unknown enters, create two 1/1 Scout creature tokens that are all colors.
Whenever a land you control enters, if it doesn't have the same name as another land you control, put a +1/+1 counter on each creature you control.

Whenever you cast a creature or planeswalker spell, if mana produced by a nonland permanent was spent to cast it, it gains trample and haste until end of turn.
{T}: Add {R} or {G}.

All lands gain “{T}: Add one mana of any color” and lose all other abilities.

Jagged Cairn enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}, {T}, Sacrifice Jagged Cairn: Draw a card.

Flying, trample
At the beginning of combat on your turn, goad all creatures with power 3 or less. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever a creature deals combat damage to an opponent, put a +1/+1 counter on it.

Trample, haste
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

Creatures you control have “Whenever this creature attacks, put a +1/+1 counter on target creature with lesser power.”
At the beginning of each end step, if there are five or more +1/+1 counters among creatures you control, destroy up to one target artifact or enchantment.

Kanvar can't attack or block.
Whenever a creature you control with power 4 or greater dies, draw a card.
{R}{G}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words “when,” “whenever,” or “at.”)

When Kin of the Rainforest enters, you may put a land card from your hand onto the battlefield.
Ascend {1}{R} ({1}{R}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

When Kindled Vengeance enters, if you cast it, create seven 1/1 green Elf creature tokens.
Whenever you attack, Kindled Vengeance deals damage equal to the number of attacking creatures to target creature or planeswalker an opponent controls.

Indestructible
As long as your devotion to red and green is less than seven, Klothys isn't a creature.
Spells you cast can't be countered.
At the beginning of combat on your turn, you may have another target creature you control assign its combat damage this turn as though it weren't blocked.

Play with the top card of your library revealed.
You may cast creature spells from the top of your library. You may cast Centaur spells this way without paying their mana costs.