Yes, very much like Spike in that aspect. It's actually a real fine story, I'm surprised it didn't take off, didn't look all that expensive (Not that it looked cheap).A form of the Master was a companion in the "Scream of the Shalka" web animations. They never really explained HOW it happened, but the Doctor had somehow put the essence of the Master into a robot body that could not leave the TARDIS, and apparently put limitations that would keep the Master from killing him (though it didn't stop him from trying thorugh omision of action). Something like that could be cool.
I might have to check that out, that's kind of like my idea about the reluctant Dalek. I was thinking along the lines of Spike(Buffy) with the inhibitor chip where he wasn't really trustworthy and his weakness would sometimes lull the protagonists into forgetting his real nature.
Anyone know why it was abandoned?