Try looking around The Yoma Clan Castle or some drifting dungeons to grab any of the managraphic images or hidden treasures in them, and you should get XP naturally from that, as well as stuff to make better gear with.
Or you could invest in make some monsters in the coliseum, as they tend to give you good XP as well as clear souls and items which you might be struggling to get at that point like certain types of mana.
Also, make sure you abuse the meteorite system, as you can get some really nice bonuses out of it, Rizelea's route actually tends to be easier because of early access to it, which says a lot.
<SaturnineTenshi> and we can play with solice because he likes it
<Solice> i hear it's better than playing with myself
<Solice> celtic had a hard time getting his ball out?
<Kana> oh man, you have no idea