Skirsdag Cultist

{R}, {T}, Sacrifice a creature: Skirsdag Cultist deals 2 damage to any target.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Weaponize the Monsters

{2}, Sacrifice a creature: Weaponize the Monsters deals 2 damage to any target.

Gut, True Soul Zealot

Whenever you attack, you may sacrifice another creature or an artifact. If you do, create a 4/1 black Skeleton creature token with menace that's tapped and attacking. (It can't be blocked except by two or more creatures.)
Choose a Background (You can have a Background as a second commander.)

Blood Rites

{1}{R}, Sacrifice a creature: Blood Rites deals 2 damage to any target.

Omnath, Locus of Rage

Landfall — Whenever a land you control enters, create a 5/5 red and green Elemental creature token.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.