msem-instigator

As long as it's your turn, Ameret is a 4/4 Angel creature with flying, haste, indestructible, and “Whenever Ameret attacks, attach any number of Equipment you control to them.”
[+2]: Create two 1/1 red and white Cleric creature tokens with lifelink.
[–3]: Ameret deals 4 damage to target creature or planeswalker. You gain 4 life.
[–4]: For each creature you control, create a Weapon token and attach it to that creature. (It's an Equipment artifact with equip {2} and “Equipped creature gets +1/+1.”)

Spells your opponents cast cost {1} more to cast.
Spells you cast cost {1} less to cast.

[+1]: Until your next turn, whenever up to one target permanent deals damage to another permanent or player, it deals that much damage to itself.
[–X]: When you cast your next noncreature spell this turn with mana value X or less, copy it. You may choose new targets for the copy.
[–2]: Create an X/X blue Spirit creature token, where X is the number of colors of mana you've spent to cast spells this turn.

[+1]: Create a tapped 3/3 black Crocodile creature token with menace.
[–1]: You may cast a copy of Size Up.
[–7]: Each land you control becomes a 3/3 Crocodile creature and gains menace and haste until end of turn.

Deception {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
As long as it's your turn, Marilye is a 3/2 Elf Rogue creature with hexproof and indestructible.
[+1]: Tap target permanent. It doesn't untap during its controller's next untap step.
[–2]: Exile the top five cards of target opponent's library. You may cast any number of cards exiled this way with total mana value less than or equal to the amount of damage dealt to them this turn without paying their mana costs.

At the beginning of your end step, you may mill two cards. If you do, you gain 2 life.
[+1]: You may discard a card. If you do, draw a card.
[–2]: Exile up to six cards from your graveyard. Create a 1/1 red and green Spirit creature token for each two cards exiled this way.
[–6]: You may cast a card from your hand or graveyard without paying its mana cost. If it has {X} in its mana cost, X is 6.

Noncreature spells your opponents cast cost {1} more to cast.
Unveil {2}{W}{U} ({2}{W}{U}: Transform this. Unveil only as a sorcery.)

[+1]: Create three 1/1 white Warrior creature tokens. They gain haste.
[0]: Until end of turn, each creature and planeswalker you control becomes a 3/3 Warrior creature and gains indestructible. (Permanents don't lose loyalty while they're not a planeswalker.)
[–2]: Choose tapped or untapped. Seto San deals 3 damage to each creature with the chosen attribute.

When Shala Na enters the battlefield, each player chooses a creature they control, then sacrifices the rest.
[+1]: Up to one target creature you control gains double strike and haste until end of turn.
[–6]: You get an emblem with “Whenever a creature dies, each opponent loses 2 life.”

Destroy target nonland permanent with mana value 3 or less. (Then exile this card. You may cast Irbek later from exile.)