Partly a post to make it easy to find the topic again, but oh well...
Anyways, to those having a hard time with any 1 boss enemy...
Get a Scaredy Cat Ring, a Bandage Ring, and a Solar Rays Ring.
If the rings are good enough on thier own, then they should work for anything about thier CL. (so getting each of these to CL 10 will benefit you in the long run)
Scaredy Cat buys time to regenerate from any beatings you are taking, and Solar Rays will hit the helpless boss while he/she/it is off in a corner somewhere (for some, like OMGWTF, get on a side that will push the boss into a corner on the same screen, otherwise they might run onto a different screen) and Bandage will heal you while you also have time to kneel to recover SP quicker.
(Works on most enemies that don't come with lackeys, so She Wolf can't be soloed because of the pups (I tried, several times at CL 5.5), unless you have a CL of 10 or whatnot...)