In a much more fannish vein:

I have often thought that what Tavros needs is a human 'moirail' the way it's most commonly interpreted; the 'enabler' aspect of human friendship could only do him good, and, as I think he would have little need for someone to keep his murderous tendencies in check for him, a traditional moirallegiance could feel uncomfortably unbalanced, which might undermine his confidence further.