Blood Furnace Boss 1 'The Maker' a dangerous boss battle The Blood Furnace is the next instance after the Hellfire Ramparts, but for some reason not many people like to do that instance. The Blood Furnace is for 62-64 players but is easily done by well geared 60s. The gear there, however, won't be much of an improvement for players with T1 or T2. Overall, it is a fast, easy instance geared for casual players.