Well, at the moment, I'm a warrior destiny hoping to get WM to R5 (going to be so much easier if and when Nexon resolves the entry into Tara issue) and Defense to R1, but after these three weeks are up, I'm hopping aboard the mage bandwagon to do something a little different.
Nobody EVER trains magic shields due to the little times we have to use it; however, that does not make it entirely useless. Imagine our next Peaca run and the boss manages to FB us. R1 fire shield will greatly reduce the damage and we won't all be murdered. Apply this to other situations like going wyvern hunting. As the shield rank increases in rank, the duration and the strength of the shield improve.
Really just asking for support here, ran the math and it's going to cost 702 ap... but with riches aplenty: an additional 60 mp after hitting r1 with all 4 shields and 36 will. Not going to be easy given the optimal training methods (wyverns orz), but all in the name of improving how we can perform in battle.