at least we are ok for say this, the quest need to feel epic in a way, why not copy what they have done in bravely default for get access to the castle of the vampire. you must beat 6 dragon really hard, why not give us Solo fight really hard that will ask some gear check and at the same time a big skill check. other game have done it before, like the secret world where get acces to the nightmare difficulty of the dungeon you need to beat the keeper alone.