One thing i like about the show is that it shows that the issue with vitrumites, and omniman, is their combination of aiblities. Super strenghty, flight, and durability. Its this trifecta that makes them so dangerous. Omniman wouldn’t have been able to destroy that civilization if he didn’t have flight and the durability to go that fast.
With Immortal, he might actually be physically more powerful than omniman, cause he caused him considerable damage and nearly gouged out his eyes. I don’t entire know if theycan regrow their eyes but that is some major damage.
Thing being, he has nowhere near omniman’s level of durability though he almost bypassed omniman’s. so that probably means his superstrength attribute is superior to omniman’s, but that damn durability.