Rem Galleu

Rem Galeu is one of the female protagonists of the series.

Background
She was born as the vessel of Demon King Krebskrem's soul, inheriting from her mother. At some point in her life, she became a Summoner and met Celestine Bordorel of the Mage's Association. Celestine wanted Rem to be part of the Mage's Association in order to keep her safe and prevent the revival of Demon King Krebskrem from her death. Rem refused and became an adventurer to find a way to defeat Krebskrem's soul on her own. After gaining a number of Summoned Beasts, Rem decided the best way to defeat a Demon King is a Demon King and decided to summon one from another world. In Starfall Tower, she came to summon a Demon King and met an elf who also wanted to summon a Demon King. They both did the summoning ritual at the same time and summoned Diablo.