Fists of stone

Through rigours of an advanced and violent training the bones in your hands and wrists have grown large, and sturdier then would normally be possible,  These clubbed hand deal increased damage when making an unarmed attack.

Your unarmed strikes now deal 1d8+Str&dex modifier however you lose the ability to wield any weapon that must be held in your hands and weapon attack will be treated as an improvised weapon