Congratulations, I think you've found the actual most brain-breaking pairing imaginable.

Don't give the generator ideas!

OMG, that would be the most entertaining trainwreck ever, and now I want it.

Me too.

There are a lot of mysteries in the Doctor's past, but I would not have imagined that to be one of them! Servalan might fit in surprisingly well with his cohort of troublesome Time Lords, though.

She would be put out that the title of The Mistress has already been taken, though.