Too many people are unnecessarily bothered over Orion being a bit too muscular. We already saw that coming at Luna's uncle's house. It's just a physical representation of how Orion is getting stronger everyday. He can use his powers of Super speed in Eternum with his real body, only a matter of time when he learns to use it in the real world. He has to be at least somewhat visibly strong for us to believe that he can hold himself against the likes of Thanatos.