Juujika no Rokunin - Vol. 5 Ch. 50 - Grip Strength

[MangaDex]

 

[Kaarme]

If you recall the incident with the first target, the MC showed how his joints are all loose. So, he has a connective tissue mutation. I reckon that same protein defect caused his nails to behave like that. Even if this overly complicated and inefficient revenge thing didn't kill him, he won't likely be in as good shape as his grandpa when he starts to grow old, due to that protein mutation.

 

[FUG_rashoumon]

Different breeds indeed.

 

[hidayato]

that's why you should use everything you have against stronger opponent. Set trap or something, don't just use brute strength, use your goddamn brain smh