I was playing in hardcore mode with the some mods with sync 1.12.2 -7.0.2 and when I enter shell storage and go to my clone, everything is fine but when I die I go back to my original self in the shell storage and I can't leave it.
The only mod that changes something when I die is Hardcore revival.
I already tried on a creative world and same thing happened, couldn't leave the shell in any game mode
(creative / survival / adventure / spectator) and the only way to leave is killing yourself but then I get stuck on another storage shell until I die and respawn normally.
And when I spawn mobs next to me they can see me and can damage me and when I press F5 I am invisible and I can punch mobs.