msem-instigator

Target player mills seven cards. Then exile two cards from that player's graveyard.

Flying
Whenever Notorious Windraider attacks, other attacking Pirates and Rogues you control gain flying until end of turn.

Flash
Whenever Nsimi's Scrambler deals combat damage to a player, look at that player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.

Target creature gets -5/-0 until end of turn. You get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)

Tap target creature. That creature doesn't untap during its controller's next untap step.

Draw three cards. If you control a Wizard, untap up to three lands.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Tap target creature you don't control.
[Lore III] Tap target creature you don't control. It doesn't untap during its controller's next untap step.

Defender
As long as your fealty to Islands is six or greater, Oasis Glutton can attack as though it didn't have defender. (Each Island you control counts towards your fealty to Islands.)

When Obscure Apostle enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Whenever you sacrifice an Idol, Obscure Apostle can't be blocked this turn.

Return target creature to its owner's hand.
Concord — If there are four or more card types among permanents you control, draw a card.

Flash
Whenever you cast an artifact or enchantment spell, put a +1/+1 counter on Observer of Secret Paths. It can't be blocked this turn.

Put target nonland permanent on top of its owner's library. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

At the beginning of your end step, create a token that's a copy of target transformed permanent you control, except it has “This permanent can't transform.”

Attacking creatures get -2/-0 until end of turn.
Metamorph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Flash
Ocean's Edge Kraken enters with a hexproof counter on it.
{6}{U}{U}, Remove a hexproof counter from Ocean's Edge Kraken: Return all other creatures to their owners' hands.

Flash
When Odaya Magistrate enters, you may counter target noncreature spell.

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.)
Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Enchant planeswalker
Enchanted planeswalker has “+2: Draw two cards, then put a card from your hand on the bottom of your library.”

Enchant creature or planeswalker
You control enchanted permanent.
Permanents you control but don't own have hexproof.

Other Merfolk you control get +1/+1.
When Olantin Pearlreader enters, scry 2. Then draw a card if you control two or more other Merfolk.

When Old Salt enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Flash
Flying

{3}{U}, Exile a card from your graveyard: Omen Serpent can't be blocked this turn.

You may have Omendancer enter as a copy of a creature you control or a Curse you control. (If it copies a double-faced permanent, it can't transform.)

Colossal 3—{5}{U} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {5}{U} as a sorcery: Put three +1/+1 counters on it if it has none.)
When Omendiver's colossal ability puts one or more counters on it, scry 3.