Talk:Fighter/@comment-81.104.204.181-20180303204027/@comment-35415494-20180429211641

The reason to take a kensai is because you can get 10 APR without gauntlets, and the class bonuses more than balance out the THAC0 and damage bonuses you would otherwise get. They cannot wear helms, but they can wear ioun stones (and i believe circlet of netheril), which can potentially be superior to helms. The AC boost is nice until AC stops mattering. Kai isn't great at high levels, as your enchantment bonus starts to become more important than the damage die used.

The difference is very slight, though. To go back to OP's question, most people make a fighter/mage or fighter>mage to be a fighter w/ mage buffs, not a mage with extra HP. From a purely powergaming perspective, a fighter(13)>mage will be able to unlock all available spell slots, and learn every mage HLA, before the ToB xp cap. You lose nothing in the long run, but requires more investment, and, as you say, you won't be able to dual until BG2.