Kunai is not good nor bad. He doesn't care about humans, he doesn't cares about what he has to do to get to his goal. Even if that means to put the whole earth on risk.

On countrary to a living being Kunai is not really "alive" he is the "dead life". A system bound in the silkbody. A being that so unstable that it makes errors in the dimension structure just by existing. He inhabits the forces of destruction and reconstruction.