msem-instigator

Return target spell or creature to its owner's hand.
Quickdraw {U} (When a creature you control blocks or becomes blocked, you may cast this spell for {U}.)

Counter target spell. If a permanent spell is countered this way, create a Gold token. (It's an artifact with “Sacrifice this artifact: Add one mana of any color.”)

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Blind Soulcaller envisions an instant or sorcery card, you may tap target permanent.

Choose one or both —
• Put target detained creature on top of its owner's library.
• Detain target creature. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Whenever Daisite Express attacks, draw a card.
Whenever Daisite Express deals combat damage to a player, discard a card.

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

Counter target instant spell.

{1}: Look at the top card of your library.
{G}, {T}, Mill a card: Untap another target creature.

Enchant artifact or creature
When Embed enters, tap enchanted permanent.
Enchanted permanent doesn't untap during its controller's untap step.

Counter target monocolored spell.

Choose one —
• Return all tapped creatures to their owners' hands.
• Return all untapped creatures to their owners' hands.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Gleaming Rider envisions an instant or sorcery card, target creature becomes a 5/5 Elk Spirit until end of turn.

When Gulchdrinker Serpent enters, detain target permanent. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

Put target creature on top of its owner's library.
Quickdraw {2}{U} (When a creature you control blocks or becomes blocked, you may cast this spell for {2}{U}.)

Flying
When High Spirits enters, target creature gains flying until end of turn.

Hexproof
Invisible Stalker can't be blocked.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Spells you cast during combat cost {1} less to cast.

Reveal the top card of your library. Draw X cards, where X is that card's mana value.

Draw three cards, then put two cards from your hand on top of your library in any order.

{2}{U}, Sacrifice Nameless Drifter: Draw a card for each creature that left the battlefield this turn.

Whenever Nightrail Printer attacks, you may tap target creature.

Reveal up to four cards you own from outside the game with the same name, then shuffle them into your main library.
Draw a card.

As long as another creature you control is attacking, Prolific Thief can't be blocked.
Whenever Prolific Thief deals combat damage to a player, draw a card, then discard a card.