I cant understand why S-Hawk would get that fruit. Mihawk is literally UNSCARRED. He doesn't need a basic defense boost like steel body and he doesn't need blade arms if he has Mihawk's style. It doesn't make offensive or defensive sense.
However, if the WG can't replicate a black blade, then maybe they thought this was the next best choice. But if that's a case, why does he even have a sword at all?
Unless this is just big setup for the "Edward Scissorhands" S-Hawk to live on The Nightmare Before Christmas island of Kuraigana. Oda could just be cramming a Tim Burton reference down our throats.