msem-instigator

Enchant opponent
Whenever enchanted player searches their library, you may search your library for a card, put it into your hand, then shuffle.

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn.

As an additional cost to cast this spell, sacrifice a permanent.
Exile target creature.

Trample
Enchantment spells and Aurashaper spells you cast cost {1} less to cast.
Whenever another enchantment you control enters, draw a card.

At the beginning of combat on your turn, if you cast an enchantment spell, an instant spell, and a sorcery spell this turn, create two 3/3 red Shark enchantment creature tokens. You may have any number of those tokens gain haste. If you do, sacrifice the tokens you chose at end of combat.

[+2]: Each opponent loses 2 life. Scry 2.
[–3]: Return target creature to its owner's hand. That player discards a card.
[–6]: You get an emblem with “Whenever a player discards a card, you may cast it without paying its mana cost.”

Enchant opponent
Whenever a creature enters under enchanted player's control, that creature gets -0/-2 until end of turn unless that player pays 2 life.

Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Whenever Merciless Bandit or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Whenever Merrow Legendmaker attacks, look at the top five cards of your library. You may reveal an Aura, Aurashaper, or Equipment card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Mettalia's Forward enters, you may salvage a card. (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.)

When Militant's Standard enters, draw a card if you control a Merfolk.
Equipped creature gets +2/+1.
Equip {2}

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
You may cast the first spell that's an enchantment, instant, or sorcery with mana value 1 you cast each turn without paying its mana cost.

When Mindbreak Artisan enters, you may search your library for an artifact card, reveal it, shuffle, then put that card on top.
Other artifacts you control have “You may choose not to untap this artifact during your untap step” and “{3}{U}{U}, {T}: Gain control of target creature for as long as you control this artifact and it remains tapped.”

{2}{R}, Sacrifice Minefield Bomber: It deals 2 damage to any target.
Cycling {2/R} ({2/R}, Discard this card: Draw a card.)

Mirrorgate enters tapped.
When Mirrorgate enters, you choose a nonbasic land card name other than Mirrorgate, then each player chooses a color.
Lands with the chosen name are lands with “{T}: Add one mana of any of the chosen colors,” and lose all other abilities, card types, and land types.
{T}: Add one mana of any of the chosen colors.

Flying, haste
Miyoga Firebird attacks each combat if able.
Whenever you cast your third instant or sorcery spell this turn, you may return Miyoga Firebird from your graveyard to the battlefield.

You may play Molten Basin from your graveyard as long as seven or more cards are in your graveyard.
Molten Basin enters tapped.
{T}: Add {B} or {R}.
Cycling {1}{B}{R} ({1}{B}{R}, Discard this card: Draw a card.)

As Moonlight Sanctum enters, choose Waxing or Waning.
• Waxing — At the beginning of your upkeep, you gain 1 life for each enchantment you control.
• Waning — Nonenchantment spells cost {1} more to cast.

Whenever a land you control enters, put a +1/+1 counter on Mountain Runt, then it deals 1 damage to up to one target creature you don't control.
When Mountain Runt has three or more +1/+1 counters on it, remove them all and transform it.

Menace
At the beginning of your end step, Mountain Tyrant deals 1 damage to each creature you don't control.

Choose one —
• Return target artifact or enchantment card from your graveyard to your hand.
• Return target creature card with mana value 2 or less from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Mystic Mackerel enters, you may have target player mill two cards.
{3}{U}, Sacrifice Mystic Mackerel: Return target enchantment, instant, or sorcery card from your graveyard to your hand.

Whenever you cast a spell from exile, you may draw a card.
At the beginning of your upkeep, you may reveal the top card of your library.