Mortal Shell has “Shells” which act like classes, you have to find the perfect one for your play style, then you have to start strengthening it. YouTuber Esoterickk decided to forego the shell and managed to beat every boss in the game. It’s like not upgrading Warren’s Exo-Rig in The Surge.
Esoterickk also beat every single boss without taking damage. So that’s a no Shell, no damage run, which is very impressive, especially as bosses will one-hit you if you’re going Shell-less. You can watch his amazing feat below.
The run is technically different from doing the Obsidian Form Shell run, which is hardcore difficulty with a useless obsidian-hued Shell, and no way to acquire any other Shells.
Esoterickk wrote this in the YouTube description.