using my hero rifle as example. i killed a lot of hollowmen at first trying to level up the bonemasher, and it only effected the handle on my hero rifle, killing alot of wolves and balverines turned weapon black, killed alot of sand furies caused the weapon to drip blood and killing lots of dark shadow dominion's gave the weapon's muzzle a black smoking aura. for a hero rifle it looks pretty damn kool. As for the bone thing on the hero sword, it only applies to the handle. after four completed games it does not seem to have any other effect's to any other part of the weapon.