For more info on HW and FW look at The Great War in  History and Lore and the White Fang in  Factions Edit
HW and FW general info Edit
HW and FW are powerful people born or created with the ability to change themselves or parts of their body into weapons with enough practice. HW and FW are born like any other person but with there aura already unlocked but for one to be created you would have to infuse your aura in to the weapon your creating right after your finished forging the weapon within twenty-four hours either HW or HW will appear or nothing will, its extremely rare for one to appear but if one does you'll have powerful ally. They also never develop a Semblance or Quirk.
Why there powerful Edit
Yes HW and WF are pretty strong by themselves but they're at they're best when there being wielded by someone they share a close bond with, whether its best friends, brothers in arms or romantic as long as they have a close bond with each other they can fight like they're a one man army with a enough of practice.