Major Mana Potion

Major Mana Potion is a potion that restores 1,008 mana.

Source
The alchemy recipe to create the Major Mana Potion is a rare (6%) drop from Darkmaster Gandling in Scholomance and can be purchased from Magnus Frostwake, a ghost in one of the buildings outside the entrance to Scholomance. Magnus is normally invisible, however; characters must complete the Scholomance quest chain "Justice for the Sarkhoffs," which begins with Doctor Theolen Krastinov, the Butcher, to see him and purchase items from him.

It is crafted using by alchemists with a skill level of 295.