Hmm "under shadowforge", you mean shadowfort? And under you mean south? Cause under shadowfort is a cyclops, and an hydra during post game, and not sure where you mean otherwise. There is a drake just south of the entrance though so probably what you mean, it kinda depends on your team and shit, but generally it's a really tough fight until lategame. If you can grab them from under and position correctly however they can't knock you away and you can spam hundred kisses on the heart, generally dies in seconds if you do that, just have some mushrooms to keep your stamina going. With a sword you'll have to wait until you get Gouge, you might have it already.