I was trying to come up with an unconventional build and thought that I have never seen someone discussing an option of dualing from mage. Definitely, the overall power might be lower than dualing the other direction, but it might be more fun to RP this different kind of character.
Something that immediately popped into my mind is ability to dual from a specialist mage into a fighter after getting some nice protective spells to increase tankiness, or learning Haste.
Or even forget about levelling too much at all. I can easily imagine a Charname growing up in Candlekeep and studying to be a mage to reluctantly follow in Gorion's footsteps. But as soon as Gorion dies, the Charname realises that even powerful spells are no match against a nice two-handed sword with cleric support, so they would start learning how to be a better warrior instead.
Casting a simple spell like Blindness or Sleep from time to time would definitely help in the beginning, and having access to scrolls and wands would definitely never hurt.
Have anyone else had some fun experience with this kind of character?