Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Soul Salvage

Return up to two target creature cards from your graveyard to your hand.

Arcane Flight

Enchant creature
Enchanted creature gets +1/+1 and has flying.

Blessing of Belzenlok

Target creature gets +2/+1 until end of turn. If it's legendary, it also gains lifelink until end of turn.

Ruin Rat

Deathtouch
When Ruin Rat dies, exile target card from an opponent's graveyard.

Rat Colony

Rat Colony gets +1/+0 for each other Rat you control.
A deck can have any number of cards named Rat Colony.

Deep Freeze

Enchant creature
Enchanted creature has base power and toughness 0/4, has defender, loses all other abilities, and is a blue Wall in addition to its other colors and types.

Demonic Vigor

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, return that card to its owner's hand.

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

Swamp

Divination

Island

Cast Down

Feral Abomination

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)