Narvin is a loyal member of the Celestial Intervention Agency, who is xenophobic, utterly convinced of his superiority and a tendency to get himself almost killed. He comes from the Big Finish audio series
Gallifrey but you don't have to know about that to play with him.
I can play him before Gallifrey is destroyed (in which case he'll be a spy who makes sure the time line is in Gallifrey's best interests) or after (when he'll be suffering with severe PTSD and survivor's guilt). Keep in mind though, that while he'll eventually warm up to your character, he's never going to be particularly cuddly.
I'll be happy to play with anyone, but I know Doctor Who universe(obviously), Due South, Star Trek, Yes (Prime) Minister, Sherlock, Tin Man, Avengers and Buffy universe better than most.