For FE Awakening Olivia is trash even if you level her up all the to level 30. But for me I used a secondary seal on and she turned into a killing machine, and the class that I've changed her into was a swordmaster. I've also turned myself into the Hero class and for the both of us combined our character rating is 305 if I was leading when were paired.
YOU DWEEBS CAN"T DEFEAT US!!!! *laughs evilly*