Mountain

Bespoke Battlegarb

Equipped creature gets +2/+0.
Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, attach this Equipment to up to one target creature you control.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Food Fight

Artifacts you control have "{2}, Sacrifice this artifact: It deals damage to any target equal to 1 plus the number of permanents named Food Fight you control."

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Pests of Honor

Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, put a +1/+1 counter on this creature.

Armory Mice

Celebration — This creature gets +0/+2 as long as two or more nonland permanents entered the battlefield under your control this turn.

Gallant Pie-Wielder

First strike
Celebration — This creature has double strike as long as two or more nonland permanents entered the battlefield under your control this turn.

Stockpiling Celebrant

When this creature enters, you may return another target nonland permanent you control to its owner's hand. If you do, scry 2.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Skewer Slinger

Reach
Whenever this creature blocks or becomes blocked by a creature, this creature deals 1 damage to that creature.

Restless Bivouac

This land enters tapped.
{T}: Add {R} or {W}.
{1}{R}{W}: This land becomes a 2/2 red and white Ox creature until end of turn. It's still a land.
Whenever this land attacks, put a +1/+1 counter on target creature you control.

Cut In

Cut In deals 4 damage to target creature.
Create a Young Hero Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Belligerent of the Ball

Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+0 and gains menace until end of turn. (It can't be blocked except by two or more creatures.)

Goddric, Cloaked Reveler

Haste
Celebration — As long as two or more nonland permanents entered the battlefield under your control this turn, Goddric is a Dragon with base power and toughness 4/4, flying, and "{R}: Dragons you control get +1/+0 until end of turn." (It loses all other creature types.)

Ash, Party Crasher

Haste
Celebration — Whenever Ash attacks, if two or more nonland permanents entered the battlefield under your control this turn, put a +1/+1 counter on Ash.

Expel the Interlopers

Choose a number between 0 and 10. Destroy all creatures with power greater than or equal to the chosen number.

Plains

Grand Ball Guest

Celebration — This creature gets +1/+1 and has trample as long as two or more nonland permanents entered the battlefield under your control this turn.