@Sep There exists a character with similar abilities in some other media I don't remember, but he was able to use his spine as a whip, and I was thinking how stupid that was, even moving the spine a bit would cause incredible damage to the entire body, severing it would be instantly fatal, even with a healing factor. My character would have to be a quick fighter, as using his ability for even a bit too long would lead to insane bleeding and flesh damage, however, he could be able to harden his bone structure to do some insane shit.
Sorry if this is nerdy, but I just am. :p