Texto em português

Each player sacrifices a creature. If you sacrificed a creature this way, you may return another permanent card from your graveyard to the battlefield.

"In rode the Lord of the Nazgûl, under the archway that no enemy ever yet had passed, and all fled before his face."

Rulings

First the active player chooses which creature they'll sacrifice, then each other player in turn order does the same, knowing choices made before their choice. Then all those creatures are sacrificed simultaneously.2023-06-16
You choose which permanent card you're returning to the battlefield, if any, as Rise of the Witch-King resolves, after permanents are sacrificed.2023-06-16
You cannot return the same permanent card that you sacrificed.2023-06-16