msem-instigator

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the next end step.)

Trample
When Arpechian Bellowers enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Search your library for a green creature card, reveal it, put it into your hand, then shuffle.

When Visiting Dignitary enters, gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Target creature fights another target creature. (Each deals damage equal to its power to the other.)

Target creature gains haste until end of turn. Make an Entrance deals 2 damage to up to one target creature.

Crocodile creatures you control get +1/+1.
Avatar of Senmut and Crocodile creatures you control can't be blocked as long as you control four or more Islands.

Attacking creatures you control get +1/+0.

Destroy target creature.
Its controller loses 2 life.

Whenever Eclipse Knight attacks, each opponent loses 1 life. You gain life equal to the life lost this way.
Eclipse Knight gets +1/+1 as long as you have 10 or more life than your starting life total.
Eclipse Knight gets +1/+1 as long as an opponent has 10 or less life than their starting life total.

Lifelink
Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)

Destroy target creature.

Return target tapped creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

{U}{R}, {T}: Fulmen deals 1 damage to target creature. When a creature dealt damage this way dies this turn, draw a card.
Whenever you cast an instant or sorcery spell, if you cast another instant or sorcery spell this turn, exile Fulmen, then return him to the battlefield transformed under his owner's control. He deals 3 damage to each creature.

Any number of target creatures you control each fight target creature with power 3 or greater. (All fight damage happens simultaneously.)

Pathway of Lost Sultans enters tapped.
When Pathway of Lost Sultans enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

When Paul, Rock Bottom dies, you may discard a card. If you do, return this card from your graveyard to your hand at the beginning of the next end step.
[+1]: Draw a card, then discard a card.
[0]: Until end of turn, Paul becomes a 2/2 Construct creature with prowess. Prevent all damage that would be dealt to them this turn.
[–3]: Return target instant or sorcery card from your graveyard to your hand.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Ride {2}{W} ({2}{W}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

You may play this card transformed.
Trample

Whenever Warhound Shuja attacks, look at the top three cards of your library. You may put a creature card with mana value less than or equal to Shuja's power from among them onto the battlefield tapped and attacking. Put the rest on the bottom of your library in any order.

Until end of turn, creatures you control get +1/+1 and gain trample and poisonous 1. (Whenever one of those creatures deals combat damage to a player, that player gets a poison counter.)

Esper Shardseeker can't be blocked.
Plainscycling {1}, swampcycling {1} ({1}, Discard this card: Search your libary for a Plains or Swamp card, reveal it, put it into your hand, then shuffle.)

Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.
Ferocious — Whenever enchanted creature attacks, if you control a creature with power 4 or greater, enchanted creature gains double strike until end of turn.

When Astute Sceneweaver enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

First mate—Your starting deck contains only cards with mana value 0, 1, or 3. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Menace
Once each turn, when one or more sources you control deal damage, you may put a +1/+1 counter on Hugo.