>>30493670>>30496842It's specifically stated not to be one.
In universe, as far as we know, it just has something to do with them. We don't know what that actually is. It could be like Zygarde where it had basically nothing to do with ruling over life nor death, just patrolling the two idiots that mess up the order from time to time.
All we know is that it specifically does not register as an official UB by the scientists who created the category in the first place.
