This individual turns out to be the Ranma from a bit over 100 years
in the future.  In the origional timeline he was brought across by a vampire,
and he's used the Nanban Mirror to come back and save his past self from this
fate.  Here's a few elements:  First off, the vampire would be protective of
Ukyo because she was the first person he killed when his hunger took control
right after his embrace.  Secondly, in his hundred years he's learned an awfull
lot, martial arts, blood magic, strategy and tactics etc.

Thirdly, he realizes the plan will never work because mirrors don't work
on vampires. :-)