msem-instigator

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Orichi of the Cold Mist enters, exile another target creature you control. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Each instant and sorcery card in your hand has cycling {2}. ({2}, Discard this card: Draw a card.)
At the beginning of your end step, if there are four or more instant and/or sorcery cards in your graveyard, you may pay {1}{U/R}. If you do, return an instant or sorcery card at random from your graveyard to your hand.

Whenever Orria Mirrorpelt becomes the target of a spell, exile that spell. If Orria Mirrorpelt was its only target, copy it for each other creature target player controls. Each copy targets a different one of those creatures.

Primal {1}{G}{G} (During your turn, you may cast this spell for {1}{G}{G} instead of playing a land.)
When Orria's Ward enters, if you played a land this turn, draw a card. Otherwise, put two +1/+1 counters on it.

Flash
Oscanthor, Trader's Ruin can't be blocked.
Whenever a creature you control deals combat damage to a player, draw a card.

Flying
Whenever an opponent casts a spell, counter it unless that player pays {1} for each spell cast before it this turn.

Flash
Flying
When Oshin enters, counter target spell if its mana value is less than or equal to the number of spells you've cast this turn.

Deception {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When Oshiruko Silencer enters, return target creature to its owner's hand.

Oshiruko Whisperwalker can't be blocked except by Rogues.
Whenever a creature is returned to its owner's hand, you may draw a card. If you do, discard a card.

{8}: Create eight 1/1 blue Tentacle creature tokens.
{8}: Counter target spell unless its controller pays {8}.
{8}: Draw eight cards.

Whenever you cast a noncreature spell, up to one target artifact or non-Aura enchantment you control becomes a 3/3 creature in addition to its other types until end of turn.

Exile the top X cards of target opponent's library. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Prowess
Foresight — When Outpost Merchant enters, if you've drawn two or more cards this turn, create two 1/1 white Bird creature tokens with flying.

Prowess
Whenever Outsider Alchemist deals combat damage to a player, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Counter target spell if you have more cards in hand than its controller.

Draw three cards, then reveal your hand.

Enchant player
Whenever enchanted player becomes the target of a spell or ability they don't control, if it isn't a copy, its controller copies it.

Counter target spell. For each other card named Overcharge in your graveyard, create a colorless Canister artifact token with “{T}, Sacrifice this artifact: Add {C}.”

Any number of target players each draw seven cards, then discard seven cards.

When Overwhelming Paperwork enters or is put into a graveyard from the battlefield, return up to one target creature to its owner's hand.
{3}{U}{U}: Sacrifice Overwhelming Paperwork. Activate only as a sorcery.

Counter target spell unless its controller pays {X}. You may cast a spell with mana value X or less from your hand without paying its mana cost.

Flying
When Owl of the Seven Stars enters, scry 2.

Flash
Flying
When P05 Suppressor enters, create a Function token with “Tap target creature. Put a stun counter on it.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Flash
Flying
Whenever you cast another spell with flash or an instant, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Flash
Flying
Whenever you cast another spell with flash or an instant, put a stun counter on up to one target creature if it's tapped. Otherwise, tap it.