The Dawn of the Witch 5 (light novel)

Saybil has spent the last three years holed up in the Forbidden Library working on his magic potions. And thanks to his work, Zero’s dream of a world where anyone can use magic is on its way to becoming a reality, as the potions spreading throughout the Great Continent give even non-magic users access to the beneficial powers of sorcery. Now, however, illegal potions are making their way to market—seemingly produced by a mysterious visitor named Har Bell, who comes from an unknown land across the fabled Ocean of Death.
Saybil, Hort, and Kudo join an elite party to seek out this New World, which, despite the advanced state of their sorcery, is suffering under the twin scourges of a mana shortage and a brutal class system. Our heroes must cross the Ocean of Death and face a world of unknowns in their quest to help Har Bell save her people!