In their rotting minds, they still quest for virtue and glory.

Lich-Knights' Conquest

Sacrifice any number of artifacts, enchantments, and/or tokens. Return that many creature cards from your graveyard to the battlefield.

Wilds of Eldraine Promos

Wilds of Eldraine

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

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.

You can choose to sacrifice zero permanents.

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.