Blind Seer

{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Stitcher's Apprentice

{1}{U}, {T}: Create a 2/2 blue Homunculus creature token, then sacrifice a creature.

Rooftop Storm

You may pay {0} rather than pay the mana cost for Zombie creature spells you cast.

Stitcher Geralf

{2}{U}, {T}: Each player mills three cards. Exile up to two creature cards put into graveyards this way. Create an X/X blue Zombie creature token, where X is the total power of the cards exiled this way.

Grimgrin, Corpse-Born

Grimgrin, Corpse-Born enters tapped and doesn't untap during your untap step.
Sacrifice another creature: Untap Grimgrin and put a +1/+1 counter on it.
Whenever Grimgrin attacks, destroy target creature defending player controls, then put a +1/+1 counter on Grimgrin.

Geralf, the Fleshwright

Whenever you cast a spell during your turn other than your first spell that turn, create a 2/2 blue and black Zombie Rogue creature token.
Whenever a Zombie you control enters, put a +1/+1 counter on it for each other Zombie that entered the battlefield under your control this turn.

Snow-Covered Swamp

Snow-Covered Island

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Gisa and Geralf

When Gisa and Geralf enters, mill four cards.
Once during each of your turns, you may cast a Zombie creature spell from your graveyard.