Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Swamp

Arcane Signet

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

Carmen, Cruel Skymarcher

Flying
Whenever a player sacrifices a permanent, put a +1/+1 counter on Carmen, Cruel Skymarcher and you gain 1 life.
Whenever Carmen attacks, return up to one target permanent card with mana value less than or equal to Carmen's power from your graveyard to the battlefield.

Plains

Sol Ring

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Orzhov Signet

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Bartolomé del Presidio

Sacrifice another creature or artifact: Put a +1/+1 counter on Bartolomé del Presidio.