gidgemuffin: no, he is not critical to the game. you can just run past him if you want. i know that some of the skeletons and ghosts and stuff in this dungeon seem pretty tough but they aren't indestructible. you should be able to deal with most of the skeletons with your battleaxe or claymore. the ghosts are a bit trickier. have you tried cloud of death from further away? as silly as it sounds, you can use the cloud of death in this dungeon. you can replenish your mana with your serpentwyne.