msem-instigator

Flying
Whenever Spellgorger Elemental attacks, discard a card at random. If an instant or sorcery card is discarded this way, Spellgorger Elemental deals 3 damage to any target. Otherwise, draw a card.

You may look at the top card of your library any time.
{T}: Target player mills a card.

When this creature enters, you may discard your hand. If you do, draw two cards.
Other Pirates and Rogues you control get +1/+1.
Once each turn, when you discard a card, you may create a 1/1 red Pirate creature token.

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
At the beginning of your end step, if Ulvenwald Howler didn't attack this turn, transform it.

Whenever you sacrifice a permanent, scry 1.
{1}, Sacrifice a nonland permanent: You gain 1 life.

Haste
Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)

Tizzanier Tidehunter can't be blocked as long as you control another Merfolk.

Pressure {U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Counter target spell.

Armed — Merciless Brute gets +2/+2 as long as it's equipped.

Tap up to one target nonland permanent and put a stun counter on it.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Flash

When Cyone, Expedition Captain enters, create a 1/1 Scout creature token that's all colors, then choose flying, first strike, or lifelink. Creature tokens you control gain the chosen ability until end of turn.
Whenever Cyone attacks, aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Up to one target creature gets -2/-2 until end of turn. Put a +1/+1 counter on up to one target creature you control.

Equipped creature gets +1/+1 and has deathtouch.
{1}: Serpent Staff becomes a 1/1 green Snake creature with deathtouch and loses all other abilities until end of turn.
Equip {3}

Double strike
Whenever you cast a noncreature spell, you may choose one that hasn't been chosen —
• Tap or untap target permanent.
• Draw two cards, then discard a card.
• Creatures you control get +1/+1 until end of turn.

Whenever you discard a card or an artifact is put into your graveyard from the battlefield, put a +1/+1 counter on Bloodhollow Bruiser.
Cycling {2} ({2}, Discard this card: Draw a card.)

Target opponent discards two cards. You gain 2 life.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Draw three cards.
5 | Add {W}{U}{B}{R}{G}. You can cast only one more spell this turn.

At the beginning of your end step, put an encroachment counter on Approach of Old Lovi, then it deals X damage to any target and you gain X life, where X is the number of encroachment counters on Approach of Old Lovi.

This spell costs {1} less to cast for each artifact you control.
Choose two —
• Creatures without flying can't block this turn.
• Two target creatures get +2/+0 until end of turn.
• Power Drive deals 3 damage to any target.

Trawler Skaab gets +1/+1 for each card put into your graveyard from your library this turn.

Whenever a creature you control enters, you may have target creature get +1/+1 and gain flying until end of turn.

Whenever Bloodcrazed Instigator attacks, target Rebel creature you control gains first strike until end of turn.

Creatures can't attack you or a planeswalker you control unless their controller pays {2} for each of those creatures.
Creatures can't block Ghastly Scraper unless their controller pays {2} for each of those creatures.