It isn't that hard. It may be hard because you do not have the buff given to you by Jalin. Near the final boss there should be an alternative route that leads you to an npc that you must save called Jalin. Doing so will give you a buff that will let you beat the final boss with ease. Unless you are complaining about the difficulty of the entire dungeon in which case I believe you must train harder in order to be the very best