msem-instigator

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Cycling {G} ({G}, Discard this card: Draw a card.)

Deathtouch
Abyss Surger enters with X +1/+1 counters on it, where X is the greatest power among creature cards in your graveyard.

{B}, {T}, Discard a card: Search your library for a card, then shuffle and put that card on top. You lose 2 life.

{T}: Adept Fisherman voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Adept Fisherman phases in, you gain 2 life.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Whenever you cast a Pirate spell, create a 1/1 blue and red Pirate creature token with haste.

Haste
Whenever two or more creatures you control deal combat damage to a player, tap those creatures, then gain control of target creature you don't control until end of turn. Untap that creature. It gains haste until end of turn. After this phase, there's an additional combat phase.

({T}: Add {U}.)
Aerie's Pillar enters tapped.
Flying
{2}{U}{U}: Aerie's Pillar becomes a creature in addition to its other types until end of turn.

Spells you cast from anywhere other than your hand cost {1} less to cast.
Whenever an opponent casts a spell with the same name as a card they own in exile or in their graveyard, that player loses 1 life and you gain 1 life.

Flash
If you would upgrade a creature you control, you may put a +1/+1 counter on it instead.
{3}{U}: Put a +1/+1 counter on Affluent Cetanthrope and draw a card.

Flash
When Agent of Deception enters, counter target creature or planeswalker spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Menace
At the beginning of your upkeep, put a prize counter on target permanent you don't control.
Whenever a permanent with a prize counter on it is put into a graveyard from the battlefield, return it to the battlefield under your control.

When Allagras' Vanguard enters, create two 1/1 blue Merfolk creature tokens with “When this creature dies, draw a card, then discard a card”.

First mate—At least half the cards in your starting deck are lands. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Trample
{1}, Discard a land card: Put a +1/+1 counter on Alvarez. He deals 1 damage to any target.

({T}: Add {U}, {R}, or {W}.)
Ancient Dominion enters tapped.

Ward {2}
When Ancient of Lotus Lake enters, draw a card.

Whenever Aravant Smuggler deals combat damage to an opponent, if it's embattled, draw a card. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

{2}{B}, Sacrifice a creature: Draw a card. You gain 1 life.

Prowess
When Arcane Dredger enters, return target instant or sorcery card from your graveyard to your hand.

Whenever Arisen Helix attacks, scry 2.
If Arisen Helix would die, exile it instead.

Haste
Whenever Arisen Hunter attacks, target player loses 2 life and you gain 2 life.
If Arisen Hunter would die, exile it instead.

Trample
Whenever Arisen Tyrant attacks, mill three cards, then you may exile a card from your graveyard. You may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 3 or less.
If Arisen Tyrant would die, exile it instead.

Flying
Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Draw a card, then discard a card.
[Lore III] Remove all lore counters from Astral Man-o'-War. Return up to one target creature you don't control to its owner's hand.

Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Atuum Serpent enters, if tribute was paid, it gains defender. (This effect lasts indefinitely.)