Mercuremon, also known as Mercurymon, was created from the Human Spirit of Steel by Cherubimon. He went with Cherubimon's plans and began absorbing the Digicode of the Digital World bit by bit. But he did not wish to serve Cherubimon forever. He later would acquire the data of Seraphimon during his battle against the Legendary Chosen to avenge the loss of the Beast Spirit of Earth. He would later evolve to Sephirothmon during his fight with the chosen to try and beat them. Inside Sephirothmon he as Mercuremon battled against Kanbara Takuya. He used Seraphimon's data to evolve into Black Seraphimon. But he was beaten and his Human Spirit of Steel was scanned. However, he still lived on a bit longer as Sephirothmon.