msem-instigator

Return target permanent to its owner's hand.
Coalesce {7}{U} (You may cast this from your graveyard for {7}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
When Risen Looter enters, if it engorged a noncreature, nonland card, draw a card, then discard a card.

Enchant creature
When Rising Tides enters, draw a card.
At the beginning of each upkeep, if enchanted creature is untapped, tap it.

Flying

When River Miscreants enters, target creature you control can't be blocked this turn.
{2}{U}: Return River Miscreants to its owner's hand. Activate only as a sorcery.

As long as your deck contains only blue and colorless cards, your minimum deck size is reduced by eight.

{U}, {T}: You may tap or untap another target creature.
Whenever one or more other creatures you control deal combat damage to a player, you may untap Riverchase Diver.

Harmony — Untap target permanent.
Whenever you cast an instant or sorcery spell, harmonize. (Trigger up to one harmony of one permanent you control.)

{7}{U}: Tap up to three target nonland permanents. This ability costs {2} less to activate if you control a legendary creature.

When Rixia, Rift Shunted enters, target creature can't be blocked this turn.
Whenever a creature you control deals combat damage to an opponent, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

When Rod of Marble Row enters, you may return target creature to its owner's hand.
Equipped creature gets +1/+1.
Equip {1}

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature deals combat damage to a player, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Whenever you cast an instant or sorcery spell, reveal the top card of your library. If an instant or sorcery card is revealed this way, draw a card.

Bleed—Reappropriate blue. (You may cast this spell by exiling two blue cards from your hand and/or graveyard if an opponent lost life this turn.)
Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Legendary creatures you control have hexproof.

Choose three. You may choose the same mode more than once.
• Return target creature with mana value 2 or less to its owner's hand.
• Scry 1, then draw a card, then discard a card.
• Target creature gets -2/-0 until end of turn and attacks this turn if able.

Target opponent looks at the top six cards of your library and separates them into a face-down pile and a face-up pile. Choose a pile, then play any number of cards from it without paying their mana costs. Put the rest of the cards into your graveyard.

Flash
Flying
Romantic Wisp can block only creatures with flying.

At the beginning of your upkeep, look at the top card of your library. If its mana value is less than or equal to the number of Scouts you control, you may reveal it and draw a card.

Flying
When Rooftop Robber enters, another target Pirate or Rogue you control gets +2/+0 and can't be blocked this turn.

Choose one —
• Counter target spell unless its controller pays {2}.
• Create a tapped token that's a copy of target token you control.

{1}{U}, {T}, Discard a card: Reveal the top card of your library. Counter target spell unless its controller pays {X}, where X is the mana value of that card.

[+1]: Tap target permanent. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
[0]: Put target artifact, instant, or sorcery card from your graveyard on top of your library. If you have an insight counter, you may return that card to your hand instead.
[0]: You get an insight counter.
[–1]: Target creature can't be blocked this turn. Until end of turn, whenever that creature deals damage to an opponent, you draw a card.

When Rune-Scribe's Apprentice enters, target player mills four cards.

Return target instant or sorcery card from your graveyard to the battlefield face down. It gains metamorph. The metamorph cost is equal to its mana cost. (It's a 2/2 creature. Turn it face up and cast it at any time for its metamorph cost.)