Warmaisach
I have 2 theories on how things might proceed. 1.) Shang follows the [Beast Warrior path] where he not only integrates beasts body-parts into his body but also their soul. Making him a host multiple souls. Or he might use abominations instead of beasts. 2.) Or once Shang loses his entire body he passes on his main consciousness to his Sword, which is quite literally himself(his reflection). And proceeds to become the strongest just as a sword.