Is the Saint of Killers truly invulnerable?

We all know that SoK is already dead, until he took on the mantle as death itself. He tanked that nuke w/o even a tear on his clothing, a point blank nuclear explosion will outright atomize you, since not being vaporized by a point-blank nuke implies that he's not composed of atoms or maybe he being a manifestation of a concept (death), physical damage does not apply to him?

I asked a similar question before.

As you said, he's already dead; you can't kill him twice. The idea is that, since his body was literally sewn back together by Satan and he was given new clothes from Hell as part of his agreement as The Angel of Death, he and his clothes are beyond that sort of thing (since you can't hurt Death, especially one which thirsts for revenge). Wikipedia says his body's composition is similar to that of a normal human, so he probably is composed of atoms (from Hell?). I think it's more the fact that he's a manifestation of the concept of death and thus cannot be harmed.

SoK and SCP-682 are two of the most hard-to-kill beings in fiction.

@the_caped_crusader: death can be "hurt". Beyonder literally killed Death in Secret Wars 2 (different Death I know)

Beyonder is above Death, so that's why he was able to "hurt" her. I was mainly talking about the humans in Preacher who tried to "hurt" the SoK, but failed, because they were below Death.