General

Currently the strongest bosser is F/P Mage.
Then comes the Luminous, and third is Battle Mage.

after the RED Update:
1) Bishop
2) Evan
3) F/P Mage

Kanna Even though we may be the glitchiest class ever and have no hypers in gms at this moment but that didn't stop me
[url=http://www.basilmarket.com/show/video/28335/0/Level_205_Kanna_GMS_Normal_Horntail_Solo.html#video_top]Horntail Solo[/url]

BAM and Evans

F/Ps and BaMs would be the most effective bossing mages, while Bishops and BaMs are also the most efficient bossers.

Evans and bishops after RED, luminous would be a good bosser too but the gms one really sucks at bossing, so unless gms changes it to kms version then its only those 2 and possibly f/p

BaM, Bishops are also pretty good bossers post-RED

What happened to Evan being the best mage bosser? o.o

F/P is the best at bossing (out of the mages)

BaM is technically best but require ridiculous amounts of funding to get over the fact that we dont hv ele reset- so i say evan or F/P unless u wanna put down da $ (u will be freakin godly if u do invest in bam tho)

F/P probably
BaM are also nice, but then if you go 150 gear, either wait for current KMST BaM buff or get a +1 attackspeed for speed cap

but on a serious note, i think F/P deals more burst dmg

If you really want to boss, don't make a mage.