Because if so that makes the erasing the 12 Universe thing even more important.

I'd also like to point out Zen'Oh power. If you look at the scene again there was really no explosion, everything just went black. This seems more like reality warping than destructive capability to me.

Yeah, he should have still been immortal. Zeno didn't know and didn't care. He erased Zamasu anyway. I think you're right, though. Zeno is a reality warper, not a fighter. His power is such that nothing can stand against him.

maybe

@beast_mode999: well zamasu became a ghost so he is above the concept of mortality,so to answer your question yes he is immortal.