Niu Lien was lucky enough to be part of Praetoria proper as opposed to the hapless, doomed rabble beyond the sonic fencing, as the orphanage matrons were sure to tell their charges. Even luckier that Cole's purge of magic was done in the city proper, so when the ancient order she had unknowningly been a part of was dead, she got offered Powers Division instead of the chopping block. The spirit of chaos was intended to be carefully diminished through activity on behalf of order, but Niu hadn't been prepared or trained as the destined bearer, and chose the name Ryobuoni despite not being in any way of Japanese descent to at least have a good time if she was going to be having to fight ghouls in the sewers.
The spirit and her began to bond in ways that would have given her parents apoplexy, as it whispered more curses, more powerful agents to use in the quest to keep her name in the lights. When she was eventually told of the Praetorian's invasion, she surprisingly went to Paragon on a diplomatic mission instead of carving a space for herself on the isles. Her press agent states that it was because of her contact with most of the Praetors - who may be powerful but couldn't lead a camping trip without backstabbing one another, let alone an invasion.
In truth, it was mainly laziness - it's easier to work in a system to reap benefits, and her reputation as a 'maverick, not used to the laws of your dimension' has gotten two blogs following her consistently, regular headlines, and a movie option.
There's another piece she learned later - while Hamidon is far weaker on Primal Earth; when she got here she thought she was a Top Dog, but the likes of the Circle of Thorns or Nemesis thrashed her like a pup. There's a lot more at play on Primal Earth than Cole realized, and a lot more to exploit. Really if someone's immolated in hellfire by ravenous demons, they cheer you on if it's a Sky Raider. Life's pretty good.
It should be noted that there's a 'ninja dispatcher' hero with similar looks to how Niu looked as a human operating in Paragon, but she and her Primal Earth counterpart really can't stand each other and do their best to ignore one another.