msem-instigator

Flying, deathtouch
Whenever an opponent loses life for the first time each turn, that player loses 1 life and you gain 1 life.

Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of it, except it has base power and toughness 1/1. If that creature had power 4 or greater, create two of those tokens instead.

Heroic — Whenever you cast a spell that targets Mira and Kalisti of Akros, copy that spell. You may choose new targets for the copy. (The copy isn't cast. A copy of an Aura spell becomes a token.)

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
{2}{G}, {T}: Create a token that's a copy of target creature token.

At the beginning of your upkeep, choose another planeswalker you control. You may activate that planeswalker's loyalty abilities twice this turn rather than only once.
[+2]: You may put a land card from your hand onto the battlefield. If you don't, each player draws a card.
[–2]: Exile target permanent. Return it to the battlefield under its owner's control at the beginning of the next end step.
[–7]: For each land on the battlefield, add one mana of any type that land could produce.

Whenever you cast a green or blue spell, create a 1/1 green and blue Elemental creature token.
Each Elemental you control enters with an additional +1/+1 counter on it.

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Create a token that's a copy of target creature you control, except it enters with an additional -1/-1 counter on it.

Flash (You may cast this spell any time you could cast an instant.)
Flying (This creature can't be blocked except by creatures with flying or reach.)

[+1]: Scry 3.
[–2]: Choose a card name, then mill a card. If that card has the chosen name, you draw three cards. Otherwise, you draw a card.
[–6]: You get an emblem with “Play with the top card of your library revealed” and “You may play the top card of your library.”

[+2]: Target player exiles a card from their hand at random. Until the end of that player's next turn, they may play that card.
[0]: Gain control of target creature or planeswalker until end of turn. Tap it.
[–9]: Take an extra turn after this one. During that turn, you control all opponents.

{1}{R}, Discard a card: Draw a card. Mist-Valley Minotaurs gets +2/+0 until end of turn.

Other Spirits you control get +1/+1.
Whenever Mistmourner or another Spirit you control enters, you may draw a card. If you do, discard a card.

At the beginning of your upkeep, you may choose one —
• Put a card from your hand on the bottom of your library. If you do, draw a card.
• Discard a card. If you do, put the bottom card of your library into your hand.

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Mold Shambler enters, if it was kicked, destroy target noncreature permanent.

Flash
When this enchantment enters, if you cast it, you may return target spell or nonland permanent to its owner's hand.
Whenever you cast your first spell during each opponent's turn, create a 1/1 white and blue Bird creature token with flying.

Target creature gets +4/+3 until end of turn. Put a trample counter on it.

Whenever you attack, you gain 1 life for each attacking creature.
{5}{W}: Put a -1/-1 counter on target tapped creature. This ability costs {X} less to activate, where X is the amount of life you gained this turn.

When Monastery Scribe enters, return target instant or sorcery card from your graveyard to your hand.

Flying

Monstrous Amalgam gets +X/+X, where X is the number of creature cards in your graveyard.
{B}, Reappropriate: Put a +1/+1 counter on Monstrous Amalgam. Activate only once each turn. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

First strike

{5}, {T}, Exile a creature you control: Exile target creature.

Moonlight Stag has vigilance as long as it has a +1/+1 counter on it.

Flash
Whenever Moonlit Hunter enters or you cast a noncreature spell, tap target permanent and untap a second target permanent.

Trample
When Moranai Outriders enters, if it's not a token, create a token that's a copy of it, except it has no mana cost.