msem-instigator

You may put a creature card from your hand onto the battlefield. That creature gains haste until end of turn. Sacrifice that creature at the beginning of the next end step unless you pay its mana cost reduced by up to {3}{R}{R}.

Flash
When Augmented Spawn enters the battlefield, create a 1/1 blue Merfolk creature token for each Island you control.
{U}, Sacrifice a Merfolk: Augmented Spawn gains hexproof until end of turn.

Menace, haste
At the beginning of combat on your turn, gain control of up to two target noncreature, nonland permanents your opponents control until end of turn. Untap those permanents. You may attach any number of Equipment among them to creatures you control until end of turn. (They unattach at end of turn.)

Whenever Aukashi, Electric Legacy enters the battlefield or equipped creature dies, attach Aukashi to a creature you control.
Whenever equipped creature deals damage to a permanent or player, Aukashi deals 2 damage to that permanent or player.
Equipped creature has double strike as long as a creature you controlled died this turn.
Equip {2}

Whenever equipped creature deals combat damage to a player, exile an instant or sorcery card from your graveyard. Then copy any number of cards exiled with Aukashi, the Rising Storm with mana value X or less and cast the copies without paying their mana costs, where X is the number of cards exiled with Aukashi.
Equip {2}

{1}, {T}, Sacrifice Aureate Panorama: Search your library for a land card that could produce each color of mana, put it onto the battlefield, then shuffle.

Flying
At the beginning of your end step, if you cast no spells this turn, scry 2.

Menace
Whenever Auros, Flame-Cursed attacks, it deals 3 damage to each opponent.

This spell can't be countered.
When Auros enters the battlefield, it deals damage to any target equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
{R}, Sacrifice Auros, Discard your hand: Draw three cards.

Whenever you play a land, return a card at random from your graveyard to your hand.
Whenever you cast a green spell, reveal the top card of your library. If it's a land card, put it into your hand. Otherwise, mill it.

Harmony — Scry 2.
{T}: Harmonize. Activate only as a sorcery. (Trigger up to one harmony of a permanent you control.)

Reach
When Automated Overwatch enters the battlefield, create a Function token with “If this spell would create one or more tokens, it creates twice that many of those tokens instead.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

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

Choose target creature or planeswalker. Its controller may exile it. If that player doesn't, they sacrifice all other creatures and planeswalkers they control.

Autumnal Boscage enters the battlefield tapped unless you control a basic land.
{T}: Add {R} or {G}.

Flying
Spirited (When this creature enters the battlefield, you may activate one of its activated abilities without paying its costs.)
{3}{U/B}{U/B}: Look at the top card of target opponent's library, then exile it face down. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell.

Deathtouch
Tribute 3 (As this creature enters the battlefield, an opponent of your choice may put three +1/+1 counters on it.)
When Avatar of Amosis enters the battlefield, if tribute wasn't paid, you may destroy target creature.

Menace (This creature can't be blocked except by two or more creatures.)
Avatar of Basat can't block.

Each other colorless creature you control enters the battlefield with an additional +1/+1 counter on it.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

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.

Vigilance
Avatar of Utsenchep can block any number of creatures.
All creatures able to block Avatar of Utsenchep do so.

Trample
Avatar of the Groves enters the battlefield with a +1/+1 counter on it for each land you control.
Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Reach, trample
If a +1/+1 counter would be put on another creature you control, instead put a +1/+1 counter on that creature and on Avatar of the Natural.

{T}: Add {C}.
Satrapies you control have “{1}{R}, {T}, Discard a card: Draw a card.”