msem-instigator

({T}: Add {G}.)
Lumbering Hillock enters tapped.
Trample
{2}{G}{G}: Lumbering Hillock becomes a creature in addition to its other types until end of turn.

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Lumenbay Flyer Line enters tapped.
{T}: Add {W}.

Whenever you cast a spell, for each of that spell's colors, create a 1/1 Scout creature token that's all colors.

Flying
Whenever another creature you control enters, you may search your library for an instant or sorcery card with the same mana value as that creature, reveal it, put it into your hand, then shuffle.

Haste
Whenever you cast a spell, if you spent mana to cast it, draw a card. Then you may cast a card with mana value less than that spell's mana value from your hand without paying its mana cost.

Whenever a creature dies, scry 1 and each opponent loses 1 life.

At the beginning of each combat, if you control a creature with flying, Magnific Wilderkin gets +1/+1 and gains flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Trample
Other Beasts you control have trample.
Whenever Magnoceros attacks, create a 5/5 green Beast creature token that's tapped and attacking.

Double strike, vigilance
Whenever Major Benjamin Stout enters, attacks, or dies, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Counter target spell. If a permanent spell is countered this way, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

[+1]: Exile up to one target tapped creature.
[–2]: Create a 4/4 white Angel creature token with flying.
[–3]: Destroy all creatures. You gain 1 life for each creature destroyed this way.
[–7]: You get an emblem with “At the beginning of each end step, you gain life equal to twice the life you've lost this turn.”

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Marinton-Ravengulch Line enters tapped.
{T}: Add {B}.

When Master Negotiator enters, you may gain control of target nonland permanent an opponent controls with mana value 2 or less. If you do, its controller may draw a card. Otherwise, you draw a card.

Menace
Foresight — Whenever you draw your second card each turn, search your library for a card, put it into your hand, then shuffle.

Instant and sorcery spells you cast cost {1} less to cast.
{U}, {T}, Exile three instant and/or sorcery cards from your graveyard: Draw a card.

When Master of Marble Row enters, choose one —
• Create a colorless Monument artifact token with “Creatures you control get +1/+1.”
• Create a white Cloister enchantment token with “When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.”

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, you may switch Master of Tranquility's power and toughness until end of turn.

[+1]: Untap up to two target creatures and/or lands.
[–2]: Choose a color. Draw cards equal to the number of creatures you control of the chosen color.
[–7]: Reveal the top ten cards of your library. Put all creature and land cards revealed this way onto the battlefield and the rest into your hand.

[+1]: Exile the top two cards of your library. You may play up to one card exiled this way this turn.
[–2]: Menna Al-Mejjat deals 3 damage to target creature. If that creature would die this turn, exile it instead.
[–6]: Draw cards equal to the number of cards in exile. Menna Al-Mejjat deals that much damage to any target.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
[+2]: Exile the top two cards of your library. Until end of turn, you may play one card exiled with this permanent.
[+1]: Exile up to two cards from your hand, then draw that many cards.
[–3]: Menna, Servant to None deals 3 damage to up to one target player and up to one target creature or planeswalker.

Flying, haste
{X}{R}{R}, Exile an instant or sorcery card with mana value X from your graveyard: Return Merkurio's Familiar from your graveyard to the battlefield. It gets +X/+0 until end of turn.

Mettalia is all colors.
Mettalia has protection from each color among cards she's salvaged in exile.
When Mettalia enters, for each color, you may salvage a nonlegendary card of that color. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

Ferocious — Whenever a creature with power 4 or greater you control enters, Mieng, Who Dances With Dragons becomes a 4/4 Dragon creature with flying until end of turn.

Discard your hand, then draw three cards.
Mindstorm's Eye deals 3 damage to any target.

When Minister of Madness enters, create a 0/1 blue Weird creature token with flying.
{2}{U}, Sacrifice a creature: Search your library for an instant or sorcery card with mana value equal to 1 plus the sacrificed creature's mana value, exile that card, then shuffle. Then you may cast that card without paying its mana cost. Activate only as a sorcery.