msem-instigator

Armed — Whenever Hordedriver Enthusiast attacks, if it's equipped, creatures you control get +1/+0 and gain trample until end of turn.

Trample

Flying, haste
At the beginning of each of your postcombat main phases, you may cast an instant or sorcery card from your graveyard with mana value less than or equal to the number of creatures that dealt combat damage to opponents this turn without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

When Host of Nature enters, create two 2/2 red and green Elk creature tokens.

Whenever you cast a noncreature spell, any number of target creatures you control get +1/+1 until end of turn.
Whenever a creature you control deals an amount of combat damage exactly equal to its mana value to a player or planeswalker, draw a card.

Whenever you make first contact, Hotshot Renegade deals 2 damage to up to one target creature or planeswalker. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Flying
When Hoverbike Courier enters, you may reappropriate. If you do, draw a card. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

When Howler Sheriff enters, gain control of up to one target creature with a bounty counter on it until end of turn. Untap that creature. It gains haste until end of turn.

Menace
Whenever Hui Zhou, the Dark Visage perseveres, you may destroy another target legendary creature. (A creature perseveres when it survives damage.)

When this creature enters, create a 2/2 black Zombie creature token. That token seeks secrets and gains haste until end of turn. (Give it that Oath Aura. Fulfill it by attacking with it and two or more other creatures to draw a card.)

Flying, haste
Whenever a battle you control is defeated, you may return Huma of Glory from your graveyard to the battlefield.

Other untapped creatures you control have indestructible.
{2}{G}{W}: Target creature gains vigilance until end of turn.

When Humored Outlaw enters, choose one —
• Put a +1/+1 counter on Humored Outlaw. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
• Destroy target artifact or enchantment.

Menace
Other Zombies you control get +1/+1.
Whenever a Zombie you control dies, each opponent loses 1 life.

Other Wolves and Werewolves you control get +1/+1.
Whenever Hungering Howlpack or another Wolf or Werewolf you control enters, you gain 2 life.

You may cast Hunter of the Moon-Serpent from your graveyard as long as you gained life this turn.

Flying, vigilance

Whenever you cast a noncreature spell, Hutao's Wardens deals 2 damage to each opponent. Then if that spell was an enchantment, scry 2.

Flash
When Icecrowned Fox enters, you may return target spell or permanent to its owner's hand.
Each untapped creature you control has “Ward—Discard a card.” (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player discards a card.)

You may have Icefang Wurm assign its combat damage as though it weren't blocked.
{4}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

Each nontoken land you control has all activated abilities of each other land on the battlefield.
When Idyll leaves the battlefield, until the end of your next turn, you gain “Each nontoken land you control has all activated abilities of each other land on the battlefield.”

Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, Iken Troubleshooter deals 2 damage to each opponent.

Trample
Whenever another nontoken creature you control dies, you may return it to the battlefield. It becomes an Aura enchantment with enchant creature you control and “Enchanted creature gets +X/+X, where X is this Aura's mana value.”

{T}, Sacrifice Ilhus, Knight of Zarad: Destroy all creatures.

When Ill-Fated Seer enters, each player sacrifices a creature. If they can't, Ill-Fated Seer deals 3 damage to them.
Revive {2}{B}{R} ({2}{B}{R}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate only as a sorcery.)