WI isn't actually good in soloing dungeons due to low defense. FA is considered the best character in this server cuz of the high dmg dealing and it can heal himself. FS also is one of the best dmg dealing character and it also has a big amount of defense. BL is pretty good, especially in bm2 if you are against a single boss, you can steal much much hp (if you retarget well), so that's it.
The characters I'd go for, are FA or FS.
P.S. Soloing MO is too hard for a newbie as you can get double hit and die.