Mannichi, the Fevered Dream

{1}{R}: Switch each creature's power and toughness until end of turn.

Baldin, Century Herdmaster

As long as it's your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin, Century Herdmaster attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Recruiter of the Guard

When Recruiter of the Guard enters, you may search your library for a creature card with toughness 2 or less, reveal it, put it into your hand, then shuffle.

Daru Spiritualist

Whenever a Cleric creature you control becomes the target of a spell or ability, it gets +0/+2 until end of turn.

Condemn

Put target attacking creature on the bottom of its owner's library. Its controller gains life equal to its toughness.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Strange Inversion

Switch target creature's power and toughness until end of turn.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Puresteel Paladin

Whenever an Equipment you control enters, you may draw a card.
Metalcraft — Equipment you control have equip {0} as long as you control three or more artifacts.

Task Force

Whenever Task Force becomes the target of a spell or ability, it gets +0/+3 until end of turn.

Angelic Protector

Flying
Whenever Angelic Protector becomes the target of a spell or ability, Angelic Protector gets +0/+3 until end of turn.

Dwarven Thaumaturgist

{T}: Switch target creature's power and toughness until end of turn.

Armored Armadillo

Ward {1} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
{3}{W}: Armored Armadillo gets +X/+0 until end of turn, where X is its toughness.

Cursed Mirror

{T}: Add {R}.
As Cursed Mirror enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Avenger en-Dal

{2}{W}, {T}, Discard a card: Exile target attacking creature. Its controller gains life equal to its toughness.

Worthy Cause

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
As an additional cost to cast this spell, sacrifice a creature.
You gain life equal to the sacrificed creature's toughness.

Gauntlets of Light

Enchant creature
Enchanted creature gets +0/+2 and assigns combat damage equal to its toughness rather than its power.
Enchanted creature has "{2}{W}: Untap this creature."

Miren, the Moaning Well

{T}: Add {C}.
{3}, {T}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Mabel, Heir to Cragflame

Other Mice you control get +1/+1.
When Mabel, Heir to Cragflame enters, create Cragflame, a legendary colorless Equipment artifact token with "Equipped creature gets +1/+1 and has vigilance, trample, and haste" and equip {2}.

About Face

Switch target creature's power and toughness until end of turn.

Imperial Recruiter

When Imperial Recruiter enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Animal Boneyard

Enchant land
Enchanted land has "{T}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness."

Entrapment Maneuver

Target player sacrifices an attacking creature. You create X 1/1 white Soldier creature tokens, where X is that creature's toughness.