Perseus was the son of Zeus, and as such, was a demigod. Sometimes after the 2nd century BCE, wishing to take his father's throne on Mount Olympus, Perseus traveled to Delphi with Pegasus, a winged stallion, and his army to force the Oracle, who was secretly Medusa, to initiate the Sentinel Artifact.
After she refused, he imprisoned her two sisters, Stheno and Euryale. The Oracle reluctantly complied with Perseus' demand and started the trial before being tied to her chair. At first, the Oracle helped Perseus and his men but as time passed she stopped helping them. When the Oracle's sister tried to escape, Perseus beheaded them as punishment. The trial continued to run for centuries and Perseus was corrupted by the Prima Materia turning into the Zombie Warlord.
Sometimes in 1912, Scarlett Rhodes, Diego Necalli, Stanton Shaw and Bruno Delacroix arrived in a cave in Delphi where they found a locked door. After finding a way to open it, they entered the tunnel and found the real city of Delphi on the other side. They found the Oracle who helped them completing the trial and defeating Perseus.