okay. i decided to make a smelting competition to show how creative you are using only a mold of diamond, extreme heat and either Broken Metal/Thermite that become laval then cooled down to form the shape of an object.
Metal Melts inside furnance ----> flows down the diamond mold with a opening in it ------> Cool it down in anyway -----> add something cool (laser/cannon etc) to make it more fun.