msem-instigator

Target creature you control gets +0/+3 and gains hexproof until end of turn.

Draw three cards. Then discard two cards unless you return a permanent you control to its owner's hand.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Return target nonland permanent to its owner's hand. If this spell was harnessed, draw a card.

Flying
Cruel Fledgling enters with a +1/+1 counter on it if six or more cards are in your graveyard.

As an additional cost to cast this spell, return a creature you control to its owner's hand.
Counter target spell.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Draw three cards.

Enchant creature
Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Enchanted creature doesn't untap during its controller's untap step.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Search target opponent's library for a creature or planeswalker card and put it onto the battlefield under your control. That player shuffles.

Whenever Lakeside Trickster becomes tapped, up to one target creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

{X}{U}{U}: Marine Monster can't be blocked by creatures with mana value X or less this turn.

Spells your opponents cast that target Onigori, Ema's Shield cost {2} more to cast.
Whenever Onigori deals combat damage to a player, that player can't untap more than two permanents during their next untap step.

Whenever Poised Koi attacks or blocks, look at the top two cards of your library, put any of them into your graveyard, then the rest back on top in any order.

Counter target spell. If a noncreature spell is countered this way, scry 2.

Vanguard — Whenever a creature you control attacks alone, gain control of target nonland permanent for as long as you control The Rocket Gang Strikes!.

Flying
When Sharp-Eyed Wingmate enters, you may return target creature to its owner's hand.

Whenever a player casts an instant or sorcery spell from their hand, you may exile that card as it resolves instead of putting it anywhere else.
Whenever Skill Sketcher attacks, you may cast a card exiled with it. That spell costs {X} less to cast, where X is Skill Sketcher's power.

Vanguard — Whenever a creature you control attacks alone, you may exile target instant or sorcery card from your graveyard. If you do, you may cast that spell from exile until your next turn. If that spell would be put into a graveyard, exile it instead.

Whenever Starlight Emissary harnesses a spell, draw a card.

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Take an extra turn after this one. Exile Temporal Aria.

Once each turn, when a creature you control becomes tapped, you may untap that creature and tap up to one target creature.

Choose target permanent. Take an extra turn after this one. During that turn's untap step, permanents other than the chosen permanent phase out until end of turn. Exile Time Stands Still.

Vanguard — Whenever a creature you control attacks alone, draw a card.

When Truffle Snuffer enters, mill three cards. When you do, choose one —
• Return an instant or sorcery card put into your graveyard this way to your hand.
• Put two +1/+1 counters on Truffle Snuffer.

You may have Undecided Mimic enter or phase in as a copy of any creature on the battlefield, except it has this ability and “{2}{U}{U}: Undecided Mimic phases out.” (Treat it and anything attached to it as though they don't exist until its controller's next turn.)