get a really big stick, or pipe, or broom whatever and a knive, hide the knife in a place where nobody will notice or search, like your bum for example. Then hide in the bathroom, wait for the bully, beat the crap out of him, knife him in the anu and cut off his balls then cut also his aquiles tendons so he cant go after you. Then go away quitly and if he ever acuses you you can say you are too small to be able to do such a thing… if youre not small just knife everybody who questions you in the bum.