msem-instigator

Menace, reach
When Surfacing Horripede enters, surveil 2.

At the beginning of your upkeep, put a +1/+1 counter on Kaur's Gift, then you gain life and add {G} equal to its power. You don't lose that mana as steps, phases, and turns end.
When Kaur's Gift dies, you gain life and add {G} equal to its power. You don't lose that mana as steps, phases, and turns end.

Equipped creature gets +2/+1 and has trample.
Whenever equipped creature attacks, other Citizens and Peasants you control get +2/+1 and gain trample until end of turn.
Equip {3}

Trample
If a creature in Imperial Guardian's pack would deal damage to a permanent or player, it deals twice that much damage instead. (Two or more creatures you control with equal power are in a pack.)

Put four time counters on target nonland permanent. If it doesn't have vanishing, it gains vanishing. (At the beginning of your upkeep, remove a time counter from that permanent. When the last is removed, sacrifice it.)

Flying
Whenever a creature attacks you or a planeswalker you control, put a -1/-1 counter on that creature.

When you discard Attack Vector, you may cast it from your graveyard.
Exile the top two cards of your library. Until the end of your next turn, you may play one of those cards.

Create a 1/1 black and red Vampire creature token with menace. If this spell was cast from a graveyard, create two of those tokens instead.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flying
{U}: Ripclaw Drake gets +1/-1 until end of turn.

({T}: Add {G}.)
Seedshrine enters tapped.
When Seedshrine enters, you may put a +1/+1 counter on target creature.

{T}: Add {C}. Put a fusion counter on Eternal Reactor.
{2}, {T}: Add {C} for each fusion counter on Eternal Reactor.

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Whenever one or more creatures you control deal combat damage to a player or planeswalker, create a Clue token.
{G}{U}, Sacrifice a Clue: Put a +1/+1 counter on target creature. Proliferate.

Lifelink
Triggered abilities of creatures you control that would trigger only when that creature enters instead trigger whenever you gain life for the first time each turn.

Equipped creature has menace.
Sacrifice an artifact or enchantment: Equipped creature gets +2/+2 until end of turn.
Equip {1}

Tempting Realms enters tapped unless you control two or more other lands.
{T}: Add {B}.
{T}, Pay 1 life: Add {U} or {R}.

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Create two tokens that are copies of target noncreature artifact or noncreature artifact card in a graveyard.

Menace
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

When Goblin Arsonist dies, you may have it deal 1 damage to any target.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
At the beginning of your upkeep, put the top card of any of your libraries on the bottom of the archived library, then you may put any card in the archived library on top of the archived library.

Equipped creature gets +1/+1 and has distorted. (It can be blocked by tapped creatures but not untapped creatures.)
Equip {1}

{T}: Add one mana of any color in your commander's color identity.

[+1]: Create a 1/1 white Cat creature token with lifelink.
[–1]: When you next activate a nonmana ability of target permanent this turn, copy that ability. You may choose new targets for the copy.
[–7]: Exile up to seven target permanents. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Reach
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Other Elementals you control get +1/+1 as long as Miroran Skycatcher has a +1/+1 counter on it.