My all time favorite versions of TMNT was Michael Zulli's run set in feudal Japan. The Turtles were demons summoned by Splinter with black magic. Ever since, I've thought of him as more of a manipulative force as opposed to the good mentor. Everything he has the Ninja Turtles do is to reach his own goal of revenge.
and yes, I have returned to the internet, don't worry I haven't been just wasting time, there's a big announcement coming soon..