What about D from the series Vampire Hunter D? Any guesses? I don't know myself...
Definitely introverted, although due more to nurture than nature I suspect.
Nobody that misanthropic could be an S, it takes dedication.
(somebody more knowledgeable about the MBTI could probably prove me wrong)
Definitely a thinker, very calm in combat, likes to talk to his enemies.
Again the lack of hatred towards his enemies suggests a Perceiver, I doubt a Judger could have a civil conversation with his enemies before killing them, although he is trying to hunt down and kill every last vampire because he couldn't fit in with human society… but then it was never suggested that they were welcoming of him either, so perhaps it's also vengeance for not letting him fit-in with them.
It takes a lot to cause it, but once a perceiver has a grudge they don’t let go.
if your calling Spike by the name of the ship, I'm going to have to re-educate you.