I am not as fond of the letter B as I am of the letter A for fictional characters. Oh, sure, it has its uses for manly types, like Byron and Bradford — think the alliterative brawny, brash, beefy. But for female characters, it implies big bosoms, bellies, and behinds in matronly names like Bessie, Bertha, and Brunhilda. The shape of the letter itself contributes, looking like a female chest turned on its side.
But if you like B better than I do, here’s some names for fantasy works.
Character names beginning with B