Many things about this character are unknown. He became the guardian of the first line of the Valhalla's road at some point in the past (possibly when Yuuko ascended to became the Valis goddess).
During the events of Valis IV, Lena Brande had to make her way to Yuuko in order to obtain the Valis sword to defeat Galgear, but she had to overcome many difficult obstacles and enemies in the way. The Babylon Guardian waited for her and her allies. When they encountered him, they engaged in battle resulting in the guardian defeated thus giving Lena the chance to advance on her way.
The Babylon guardian is a serious and protective spirit. He wouldn't let anybody enter to Valhalla without defeating him, even if his life is taken during the battle. He seems to know Asfal.
The Babylon guardian's physical body in enormous and only consists on a head and two hands, making easy for him trying to reach enemies with his body parts. He can levitate and throws many giant sparkballs from his hands. His head is his only weakpoint.
The Babylon guardian appears in the PCE-CD version of Valis IV as the second boss being the first guardian of the Valhalla road at the end of the Babylon stage.
- Galgear's final form's body structure is similar to that of the Babylon guardian, although his position and attacks are totally different.
- The sparkballs he throws from his balls serves as enemies in Babylon and Valhalla's road, even though he was defeated after the Babylon stage.