Sorry Tristan, but my favourite redheaded bi-sexual (maybe in fan-fic. If she was in Torchwood she’d probably be bi.) time-traveler is Amy Pond, who also came back fairly recently. (Is Tristan meant to be red-headed? She looks more blonde to me, or does she dye it?)
Tristan was ORIGINALLY intended to be a redhead, however, because I didn’t want to have mix a consistent reddish shade of watercolor for every strip, I went with the more yellow shade. You’re free to call it whatever you want!
There won’t be any crossing over, but Tristan would totally have a crush on Amy Pond. (Heck, *I* have a crush on Amy Pond, and I’m straight!)