msem-instigator

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

You may have Imitator of Success enter the battlefield as a copy of any creature on the battlefield, except it has no mana cost and base power and toughness 1/1 if it's a token.
Successor {1}{U}{U} ({1}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost and base power and toughness 1/1. Succeed only as a sorcery.)

You may have Insipid Metamorph enter the battlefield as a copy of any other creature on the battlefield, except it's 1/1.

[+1]: Each player may draw a card. For each opponent who does, put a loyalty counter on Rahit.
[–1]: Each player draws three cards, then puts two cards from their hand on top of their library in any order.
[–6]: You get an emblem with “Discard a card with mana value X: Counter target spell with mana value X or less.”

Whenever you innovate, put a loyalty counter on Volta the Innovator. (You innovate as you cast a spell, draw a card, or have a land enter beyond the first of each in a turn.)
[–2]: If you would draw a card this turn beyond the first, draw twice that many cards instead.
[–3]: Whenever you cast your second spell this turn, copy it.

Vanishing 1 (This permanent enters the battlefield with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When the last time counter is removed from Conspiracy of Ravens, target player reveals their hand. You choose a nonland card from it. That player discards that card.

{B}, {T}, Pay 1 life, Discard a card, Sacrifice Dark Rite Cultist and another creature: Create a 5/5 black Demon creature token with flying.

If an effect would cause an opponent to discard one or more cards while they have fewer than that many cards in hand, they lose life equal to three times the difference instead of discarding the excess cards.

Destroy target creature or planeswalker.

When Ravenous Chupacabra enters the battlefield, destroy target creature an opponent controls.

[+1]: Until end of turn, you may cast a creature card from your graveyard. Creature spells cast this way cost {2} less to cast.
[–2]: Each player discards a card. For each player who discarded a creature card this way, create a 2/1 black Horror creature token.
[–6]: For each player, you may put a creature card from that player's graveyard onto the battlefield under your control.

Search your library for a nonland card not named Thin the Veil, exile it, then shuffle. If it has mana value less than or equal to the number of card types among cards in your graveyard, you may cast it without paying its mana cost. If you don't, put it into your hand.

As long as an opponent has one or fewer cards in hand, Valdez gets +2/+0 and has menace.

Other creatures you control can't attack or block alone.

Haste
Whenever Carnival Daredevil deals combat damage to a player, exile the top card of your library.
Duet — You may play cards exiled with Carnival Daredevil as long as you control exactly two tapped creatures.

Casualty of War deals 4 damage to target creature or planeswalker.
{2}{R}{R}, Exile Casualty of War from your graveyard: Arm up to two target creatures you control. Activate only as a sorcery. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

[+1]: Haide Bankbuster deals 2 damage divided as you choose among one or two targets.
[+1]: Draw two cards unless any player has Haide Bankbuster deal 3 damage to them.
[–9]: Until end of turn, gain control of all permanents target player controls and they gain haste. Untap those permanents.

Obliterating Blast deals 3 damage to any target. A creature dealt damage this way this turn can't be regenerated this turn. If that creature would die this turn, exile it instead.

Spirited (When this creature enters the battlefield, you may activate one of its activated abilities without paying its costs.)
{1}{R}, Discard a red card: Roggar deals 2 damage to any target. This damage can't be prevented.
{2}{R}, Exile a red card from your graveyard: Create two tapped 1/1 red Elemental creature tokens.

Flying
Spirited (When this creature enters the battlefield, you may activate one of its activated abilities without paying its cost.)
{3}{R}{R}, {T}: Exile an instant card with mana value 3 or less from your graveyard, then cast a copy of a card exiled with Thunderlash Mystic without paying its mana cost.

Mountains you control have “{T}: Add {R}{R}.”
[+1]: Exile the top card of your library. You may play that card until end of turn. Untap a Mountain you control.
[–2]: Conjure six cards named Scorch. Shuffle them and your hand into your library, then draw two cards.

Return up to one target creature card and up to one target noncreature permanent card with total mana value 4 or less from your graveyard to the battlefield.
Exile Beckon the Damned.

When Earthenlore Disciple enters the battlefield, you may destroy target artifact, enchantment, or land.

[+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.

{T}: Add {G}. If you control an attacking creature, add one mana of any color instead.