Lich-Knights' Conquest

• WWizards of the Coast2023-09-01
  Official Ruling
  An artifact creature or enchantment creature sacrificed to Lich-Knights' Conquest may be one of the cards chosen to be returned.
• WWizards of the Coast2023-09-01
  Official Ruling
  If any abilities trigger as you sacrifice permanents, those abilities won't be put onto the stack until after you've returned creature cards from your graveyard to the battlefield.
• WWizards of the Coast2023-09-01
  Official Ruling
  You sacrifice the artifacts, enchantments, and/or tokens as part of the resolution of Lich-Knights' Conquest. It isn't an additional cost. If Lich-Knights' Conquest is countered, you won't sacrifice anything.
• WWizards of the Coast2023-09-01
  Official Ruling
  You can choose to sacrifice zero permanents.

Rulings via Scryfall