Unbroken, Unstoppable, Unmatched

In the Dragon Continent, spirit beasts can be awakened and bonded, and the families that produce strong beast tamers send their children to the Myriad Gods Legion. Cole Hawke could not awaken anything. He was written off as trash until a system bound him to the Supreme Soul Beast Prison, a penitentiary holding the most dangerous creatures on the continent, with Cole as its warden. When the Legion opened its recruitment examination, he signed up. During the trials he used the Prison to tame rare soul beasts and beat the geniuses sent by the great families, which drew the attention of the whole army. After that came legion training, expeditions into forbidden grounds and secret realms, and fighting against other races. Each one unlocked another function of the Prison, and he contracted stronger beasts, up to SSS rank. The people who mocked him started treating him with wary respect.