msem-instigator

Whenever you gain life, put a +1/+1 counter on Listless Maneli.
Surpass {5}{W} ({5}{W}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Flying, lifelink
Sacrifice a creature: Until end of turn, Turned Watcher gets +1/+0 and gains “Whenever Turned Watcher deals combat damage to a player, draw a card.”

Exchange control of target creature you control and target noncreature spell an opponent controls. You may choose new targets for that spell.

Scorch deals 3 damage to any target.

You may have Unstable Impersonator enter as a copy of any creature on the battlefield chosen at random.

Flying, vigilance

First strike
Whenever Guardian of the Eclipse attacks, you may exile another target attacking creature you control, then return it to the battlefield under your control tapped and attacking.

Scoundreleo enters with a +1/+1 counter on it if a creature you controlled dealt combat damage to a player this turn.

Whenever Erebos's Whipslang or another enchantment you control enters, each opponent loses 1 life and you gain 1 life.

Flying, lifelink
Other creatures you control have lifelink.

Create three 1/1 white Soldier creature tokens. Scry 3.

When Leafguard Larva enters or a creature you control scavenges it, return target card from your graveyard to your hand.
Scavenge {3}{G} ({3}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When Sea's Allure enters, gain control of target creature for as long Sea's Allure remains on the battlefield.

Haste
{2}{W}, {T}: Hair-Trigger Marshall deals 2 damage to target blocking creature.

I, II — Put a +1/+1 counter on target creature you control.
Discovery — Creatures you control with +1/+1 counters on them have lifelink.

Enchant creature
As Legacy of Frondpond enters, choose a creature type.
Enchanted creature gets +2/+1, has deathtouch, and is the chosen type in addition to its other types.

Whenever you cast an artifact spell, create a 1/1 colorless Construct artifact creature token.

Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them and create a Masterpiece token of your choice.)
When Bottled Lightning enters, it deals 3 damage to any target. Scry 1.

Exile up to two target permanents you control, then return those cards to the battlefield under your control.

Whenever Illumination Savant attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Put a +1/+1 counter on each artifact creature and enchantment creature you control.

Flying
Div of the Endless Thought has all activated and triggered abilities of all other permanents on the battlefield.

({T}: Add {R} or {W}.)
Whenever Forgotten Steppe becomes tapped, you lose 1 life unless you control two or more basic lands.

Flying, haste
Miyoga Firebird attacks each combat if able.
Whenever you cast your third instant or sorcery spell this turn, you may return Miyoga Firebird from your graveyard to the battlefield.

Whenever you attack, you may discard a card. If you do, exile the top two cards of your library. You may play one of them this turn.
Once each turn, when a card leaves your graveyard, you may add {C}{R}.

Return target nonland permanent to its owner's hand.
Exile target nonland permanent you control, then return it to the battlefield under your control.