msem-instigator

When Gulchdrinker Serpent enters, detain target permanent. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

{B}{G}{U}, Discard a card named Gusma, God of Creation: Gusma gains indestructible and becomes a God creature in addition to its other types.
Whenever Gusma enters or attacks, add {B}{G}{U} and draw a card. You don't lose this mana as steps, phases, and turns end.

At the beginning of combat on your turn, for each permanent type, aetherize up to one target permanent you control of that type. (To aetherize, create a token that's a copy of it, then exile that token.)

Whenever Halford enters or attacks, an opponent chooses one. When they choose one that has already been chosen, copy that ability.
• That opponent loses 2 life and you gain 2 life.
• That opponent sacrifices a permanent.
• That opponent discards a card. If they can't, draw a card.

Hexproof
Deploy 4 (As this enters, you may tap any number of other creatures you control with total power 4 or more.)
When Hamlet Witch enters deployed, return target card from your graveyard to your hand.

Flying
Whenever Hao'Tai deals combat damage to a player, that player exiles the top five cards of their library and separates them into two piles. Put an ember counter on each card in the pile of your choice. You may play cards from exile with ember counters for as long as they remain exiled.

Flying
At the beginning of your first main phase, you may put any number of land cards from your hand onto the battlefield, then draw a card for each land put onto the battlefield this way.

Trample
Other Dwarves and Elves you control get +1/+1.
If Harl and Finn or another Dwarf or Elf you control entering the battlefield or attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

{W}: Target creature assigns combat damage equal to its toughness rather than its power this turn.

At the beginning of each player's upkeep, sacrifice Hayuan, the Misjudged if that player controls a creature with power 2 or less.
When Hayuan dies, create X Idol tokens, where X is the number of creatures you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Colossal 5—{8}{W}{W} (You may cast this for its colossal cost to have it enter with five +1/+1 counters; or pay {8}{W}{W} as a sorcery: Put five +1/+1 counters on it if it has none.)
Ward {5}
When Hekaton Dismantler's colossal ability puts one or more counters on it, tap each creature you don't control. Those creatures don't untap during their controller's next 100 untap steps.

Trample
Resolute — At the beginning of combat on your turn, if Helicos Gargantua's power is greater than its base power, double its power until end of turn.

This spell costs {X} less to cast, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Trample

Flying
Whenever Hellkite Omnivore attacks, you may have it consume. If you do, put a +1/+1 counter on Hellkite Omnivore. When a creature is sacrificed this way, Hellkite Omnivore deals 3 damage to any target. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Whenever a nontoken creature you control dies, create a 1/1 colorless Spirit creature token with flying.

Flying, prowess
If you would draw a card, scry 1, then draw a card instead.
Whenever an opponent casts a spell, if it's not their turn, draw a card.

Flash
When Herald of Wisdom enters, you may cast target instant or sorcery card with mana value 4 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Flying
Whenever Heroes of Wars Past attacks, attacking Human creatures get +1/+1 and gain flying until end of turn.

Flash
When Highpoint Guru enters, scry X, where X is the number of Monks you control.

Defender, deathtouch
Homestead Watcher gets +2/+0 and can attack as though it didn't have defender as long as you control another creature with defender.

Trample, haste

Indestructible
You have no maximum hand size.
Whenever an opponent draws a card, you draw a card.
If you would lose the game other than for having 0 or less life, you win the game instead. (Another player winning the game does not cause you to lose the game.)

Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
Ifram's Greenfur must be blocked each combat if able.

{G}{U}{R}, Discard a card named Ifram, God of Chaos: Ifram gains indestructible and becomes a God creature in addition to its other types.
Whenever Ifram enters or attacks, choose target non-God permanent. Its owner shuffles it into their library, then its controller reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Ward—Pay 3 life.
Igniderm enters with three ignition counters on it.
At the beginning of your upkeep, remove an ignition counter from Igniderm. If you can't, sacrifice it.