msem-instigator

Whenever you cast an instant or sorcery spell, target creature can't block this turn.

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Destroy target artifact or enchantment [with mana value 3 or less].

When Ryleth, Vengeful Shadow enters, create two 1/1 green Elf creature tokens.
Whenever you attack, you may pay {1}{B/G}. When you do, return target creature card with mana value less than or equal to the number of attacking creature tokens you control from your graveyard to the battlefield tapped and attacking.

Choose one or both —
• Put a +1/+1 counter on each of up to two target creatures.
• Put a +1/+1 counter on up to one target Elemental and up to one target Soldier.

When Weaver of Mists enters, substantiate target card in your graveyard. (Put it onto the battlefield face down as a 2/2 creature. You may turn it face up and cast it at any time for its mana cost if it isn't a creature.)
Spells you cast from anywhere other than your hand cost {1} less to cast.

Choose target artifact, creature or planeswalker. If this spell was foretold, you may destroy it. Create a token that's a copy of it except it isn't legendary, has haste and “At the beginning of the end step, sacrifice this permanent.”
Foretell {B}{B}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Whenever a permanent enters under an opponent's control, reveal the top card of your library. If it's a permanent card that shares a type with that permanent, you may put it onto the battlefield. Otherwise, put it on the bottom of your library.

Temple Recluse gets +1/+0 as long as you've cast a noncreature spell this turn.

[+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.

Choose two —
• Each opponent sacrifices a creature.
• Each player discards two cards.
• All creatures get -1/-1 until end of turn.
• You draw two cards and you lose 2 life.

Reveal cards from the top of your library until you reveal a card with a lesser mana value than the previous card, then put all cards revealed this way into your hand.

{G}{W}, {T}: Remove a -1/-1 counter from target creature.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

{T}: Draw a card, then discard a card.

First strike (This creature deals combat damage before creatures without first strike.)

Spend only black mana on X.
Any number of target players each draw X cards and lose X life.

Whenever Fallacy's Channeler becomes untapped, each player sacrifices a creature.
{T}, Pay 1 life: Fallacy's Channeler deals 1 damage to any target.

Reach
As Celestial Principality enters, choose a number.
Noncreature spells with mana value equal to the chosen number can't be cast.

When Holy War enters, create three 1/1 white Cleric creature tokens.
Creature tokens you control have first strike and lifelink.

Creatures have “Whenever this creature attacks or blocks, it fights another target creature.”

Tyrant of the Depths has hexproof as long as it's untapped.
Whenever you cycle Tyrant of the Depths or it attacks, tap target nonland permanent you don't control and put a stun counter on it.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

Enchant creature
When Sylvan Majesty enters, search your library for a Forest card, put it onto the battlefield tapped, then shuffle.
Enchanted creature gets +3/+3.

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Whenever you cast an enchantment spell, create a 1/1 white and black Bird creature token with flying and vigilance.
Whenever three or more creatures you control deal combat damage to a player, that player sacrifices a creature. If they can't, they discard a card.

Equipped creature gets +2/+1 and has menace.
Whenever equipped creature deals combat damage to a player, they sacrifice two permanents.
Equip—{2}, Sacrifice a creature.

{R}: You may put a Rebel creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.