Upon entering Stormveil Castle, you'll have two main paths: the main gate (guarded by a powerful Nightbound Omenkiller) or the more discreet side path suggested by Gatekeeper Gostoc. For your first playthrough, the side path is generally safer. Navigate the ramparts, dealing with Nightbound Banished Knights and the new 'Shadow Imp' enemies that ambush from dark corners. Look for the 'Rusty Key' near the kitchen area to unlock a shortcut. activate the 'Rampart Tower (Nightfall)' and 'Liftside Chamber (Nightfall)' Sites of Grace. The castle's interior now features more traps and areas of complete darkness, requiring the use of a torch or lantern. Collect the 'Hookclaws (Nightfall)' from a corpse near the main courtyard, as they are excellent for early-game bleed builds.
