Dark Intimations

Each opponent sacrifices a creature or planeswalker of their choice, then discards a card. You return a creature or planeswalker card from your graveyard to your hand, then draw a card.
When you cast a Bolas planeswalker spell, exile Dark Intimations from your graveyard. That planeswalker enters with an additional loyalty counter on it.

Visions of Ruin

Each opponent sacrifices an artifact. For each artifact sacrificed this way, you create a Treasure token.
Flashback {8}{R}{R}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Vona's Hunger

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Each opponent sacrifices a creature of their choice. If you have the city's blessing, instead each opponent sacrifices half the creatures they control of their choice, rounded up.