2023-09-01 : An artifact creature or enchantment creature sacrificed to Lich-Knights' Conquest may be one of the cards chosen to be returned.

2023-09-01 : 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.

2023-09-01 : You can choose to sacrifice zero permanents.

2023-09-01 : 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.