Wernog, Rider's Chaplain

When Wernog, Rider's Chaplain enters or leaves the battlefield, each opponent may investigate. Each opponent who doesn't loses 1 life. You investigate X times, where X is one plus the number of opponents who investigated this way.
Friends forever (You can have two commanders if both have friends forever.)

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature of their choice.

Othelm, Sigardian Outcast

{2}, {T}: Choose target creature card in your graveyard that was put there from the battlefield this turn. Return it to the battlefield tapped.
Friends forever (You can have two commanders if both have friends forever.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Viscera Seer

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

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Woe Strider

When Woe Strider enters, create a 0/1 white Goat creature token.
Sacrifice another creature: Scry 1.
Escape—{3}{B}{B}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Woe Strider escapes with two +1/+1 counters on it.

Dockside Chef

{1}{B}, Sacrifice an artifact or creature: Draw a card.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.