[Once he catches even an ounce of that familiar presence, there's no force in any world that's going to stop him from following it to the source.
...admittedly, the more the world around him starts to echo Acid Tokyo, the more his skin starts to crawl and his heart hammer in his chest, but he would do almost anything to see his princess again. And if she's somehow ended up in this world, he has to find her before anything can happen to her. "Sides" be damned.
When he reaches the reservoir he does finally remember a bit of self-preservation, moving quietly and calling out in a soft voice:]