The Grand Mana Potion is a craftable post-Ancient tier potion that restores 400 mana, and inflicts the Mana Sicknessdebuff upon use. It can also be purchased for 5 from the Mushman after all Ancients have been defeated.
When using Recipe Browser, it shows the materials used to craft these potions as "Any Ancient material". And since the Hardmode Ancients' rematch materials aren't used to craft them, it means this potion will eventually be craftable with any material that would drop from Ancients post-Equinox Worms.