msem-instigator

Choose one —
• Counter target noncreature spell.
• Peer into the Cosmos deals 3 damage to target creature.
• Until end of turn, damage that would reduce your life total to less than 1 reduces it to 1 instead.
Monument {1}{U}{R}{W} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

When Peeto enters, scry 2.
Whenever a Scout you control attacks, choose land or nonland, then look at the top card of your library. If it's a card of the chosen kind, you may reveal it and draw a card.

Pelagic Hydra enters with seven +1/+1 counters on it.
{1}{G}: Put a +1/+1 counter on Pelagic Hydra.
Remove a +1/+1 counter from Pelagic Hydra: It deals 1 damage to target creature blocking or blocked by it.

Double strike

When Pelt's Refuge enters, if {G} was spent to cast it, distribute two +1/+1 counters among creatures you control.
Whenever a creature you control dies, draw a card.

Equipped creature gets +1/+1 for each creature you control.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Whenever Penny and Pete attacks, gain control of up to one target noncreature permanent and up to one target creature until end of turn. Untap the noncreature permanent, then tap the creature. It's attacking.

When Pensive Muse enters, create a white Aura enchantment token named Seal's Love attached to target creature you control. The token has enchant creature and “Enchanted creatures you control get +1/+1.”

When Pensive Songwriter enters, you may copy and then exile an instant or sorcery card with mana value 2 or less from your hand. Cast the copy without paying its mana cost. You may cast the card as long as it remains exiled.

At the beginning of each main phase, each player adds {W}{U}{B}{R}{G}.

When Percy's Perfect World enters, search your library for a legendary white card, reveal it, put it into your hand, then shuffle.
If an effect would create one or more creature tokens under your control, it creates twice that many of those tokens instead.

Green creatures you control have “{T}: Add one mana of any color.”
Red creatures you control have “{1}, {T}: This creature deals 1 damage to target player.”
White creatures you control have “{2}, {T}: Tap target nonland permanent.”

Protection from tokens
[+1]: Each player may draw a card. For each opponent that does, you gain 1 life and create a 1/1 colorless Construct Actor creature token
[–2]: Each player sacrifices a creature. Create a token that's a copy of a creature sacrificed this way.
[–7]: Until end of turn, each creature you control becomes a 6/6 black Horror creature with trample, menace, and lifelink.

Madness {4}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
Target creature gets +4/+4 until end of turn. Put a trample counter on it. If this spell's madness cost was paid, all creatures able to block that creature this turn do so.

When this enchantment enters, create your choice of a 1/1 red Dwarf creature token or a 1/1 green Elf creature token.
At the beginning of combat on your turn, up to one target Dwarf and up to one target Elf each get +1/+0 and gain first strike until end of turn.

Look at the top four cards of your library. Put two of them into your hand and the rest on the bottom of your library in a random order. Create a tapped Treasure token.

Perfect the Models deals 3 damage to any target and you gain 3 life. You may play an additional land this turn.
{5}{B}{R}{G}, Exile Perfect the Models from your graveyard: Create three 3/3 black Demon Horror creature tokens. They gain haste and indestructible until end of turn. Activate only as a sorcery.

First strike
Prevent all damage that would be dealt to creatures you control by sources with greater mana value.
{2}{W}{W}: Create a 1/1 colorless Construct Actor creature token. Put a vigilance counter on it.

At the beginning of your upkeep, each player discards a card. Then if a player has no cards in hand, you may transform Performer of Ambition.

Menagerie — If there are five or more creature types among creatures you control, you may search your library for a card, then shuffle and put that card on top.
You draw two cards and you lose 2 life.

Target player discards two cards. Forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Exile target land. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Whenever a creature dies, scry 1.
{2}{U}, Exile a creature card from your graveyard: Draw a card.

Trample
When Pernicious Primavore enters or dies, destroy up to three target artifacts and/or enchantments.

Untap all artifacts you control during each other player's untap step.
Tap two untapped artifacts you control: Target player mills two cards.