Vestigium Titano Rgis is a Custodes, a guardian, named for his grandfather, the greatest of all the Custodes. After their home is overrun and taken over by demons, he and his family are forced to flee. Leaving his father behind forever.

After a dreadful accident before Ves is even fourteen years old leaves a demon bonded to his soul, he is forced to leave the rest of his family, striking out on his own to discover his destiny.

With the help of a witch, a goddess, and a plethora of mythical beasts, he finds acceptance among strangers and learns the extent of his true Custodes power, but is it enough to finish off the demon clawing at his soul before it destroys him forever?