Eversoul is a role-playing idle gacha game set in a world where humanity has been wiped out by a cataclysmic world war and failed evacuation. In this world, magical beings called Souls are born from artifacts left behind by humanity and are rebuilding their world, Eden, until a mysterious gate brings forth monsters from an unknown place. Queen Yuria and Mephistopheles perform a ritual to summon a hero from the past to help the Souls access greater power and fight against the threat.
This hero is the player, known as the Savior, who leads the Souls into battle and is responsible for their growth and development. In battle, the player can activate the Souls’ Active and Ultimate skills to turn the tide. Out of battle, the player can level up the Souls, upgrade their stats, and form bonds with them through the Bond System. The player is also in charge of their own town, which they can customize and protect from monsters.