You can also obtain Superior ability crystal by fighting bosses in the open world which gives you XP multiplier.
Yeah I know but like I said I ended up trying to use Mad chimera as a way to level up and around 300 is where levels started to dwindle I also found in the version i had been playing 5.3 that at a certain size you couldn't talk to companions once they grew too big but 5.4 seems to fix this. As I said in my post I'd like to get to around level 700 or so but again it's hard to when the more levels you have the slower the exp gain. I'd fight Bandit boss but well he ends up getting strong enough to kill both me and Bunshido and due to this my ego bar resets and it's a pain to get back up so thus why I grinded Mad chimera as I can take her weapons away.