msem-instigator

As this permanent transforms into Velir, put four loyalty counters on it.
[+1]: Draw two cards, then discard two cards unless you discard a land card.
[–2]: Search your library for a multicolored card, reveal it, put it into your hand, then shuffle.
[–4]: Exile target permanent.

Whenever Playful Surveyor attacks, reveal the top card of your library. If that card shares a color with a permanent you control, you gain 2 life.

Ash Freebooter has first strike as long as it's attacking.
When Ash Freebooter enters, you may discard a card. If you do, draw a card.

{T}, Exile a card from your graveyard: Scry 1.

When Leafmantle Dryad enters, if you control a legendary creature, you may search your library for a basic land card and put it onto the battlefield tapped, then shuffle.

Put target spell or nonland permanent on top of its owner's library.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

(Transform this if it's not attached to a creature. Pay {3}{B} as a sorcery to unattach it.)
Enchant creature you control
Corrupted Mount's rider gets +5/+4 and can't block.

{2/W}{2/W}: Shrapnel Golem deals 3 damage to target creature blocking it.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of combat on your turn, target creature you control with mana value 3 or less can't be blocked this turn. If Streetwise Investigator has two or more counters on it, that creature gains vigilance until end of turn.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{G}: Mill three cards. Target creature gets +X/+X and gains trample until end of turn, where X is the number of land cards in your graveyard.

{B}{R}, {T}, Sacrifice Heretical Soulshifter: Return target creature card from your graveyard to the battlefield. It gains haste until end of turn. Activate only as a sorcery.

When Howler Sheriff enters, gain control of up to one target creature with a bounty counter on it until end of turn. Untap that creature. It gains haste until end of turn.

Once each turn, you may cast a creature spell with mana value less than or equal to the number of names noted for Genetic Breakthrough without paying its mana cost.
{G}, Sacrifice a nontoken creature with a name not noted for Genetic Breakthrough and note its name: Draw cards equal to the sacrificed creature's power, then discard two cards.

Spells your opponents cast cost {2} more to cast for each card with the same name as that spell in that player's graveyard and for each nonland permanent on the battlefield with the same name as that spell.

When Jerrold's Wretched Cure enters, search your library for a legendary green card, reveal it, put it into your hand, then shuffle.
At the beginning of your upkeep, up to one other target nonland permanent you control becomes an X/X Construct creature in addition to its other types until end of turn, where X is the number of card types among cards in your graveyard.

Flash (You may cast this spell any time you could cast an instant.)
When Sanguine Muralist enters, you may have target creature's toughness become 1 until end of turn.

During your opponents' turns, Chroma, the Faerie Circle has all basic land types in all zones.
Chroma, the Faerie Circle enters tapped.

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.

Civilization's Cost deals damage to each player equal to the number of nonbasic lands that player controls.
Flashback {R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tap up to two target creatures. Germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

[+1]: Draw a card, then discard a card.
[–2]: Fulmen, Aether Prodigy deals 2 damage divided as you choose among one or two targets. Draw a card.
[–6]: Whenever you cast an instant or sorcery spell this turn, copy it. You may choose new targets for the copy.

Primal {1}{B} (During your turn, you may cast this spell for {1}{B} instead of playing a land.)
Each opponent discards two cards.

Choose one —
• Tap target creature.
• Untap target creature and remove it from combat.
Draw a card.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
When Keeper of Holy Lands enters, you may search your library for an enchantment card, reveal it, then shuffle and put that card on top of it.

Colossal 2—{6}{U} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {6}{U} as a sorcery: Put two +1/+1 counters on it if it has none.)
When Titanic Fathomclaw's colossal ability puts one or more counters on it, return target instant or sorcery card from your graveyard to your hand.