Guess the game is made to be played this way... Maybe getting less and and less xp from the same creature would help...
Well. If you have all the weaknesses. Nara is enough to make you just want to restart the game. XD
By the way, you climb up to Nara and face her you're good enough
you see, that is a thing, there's just a minimum in the amount of xp you get from the monster.