Now this one was pretty creepy. I thought the regular Ultra Space areas had rather creepy music, but this one just tops it.
You can tell that a lot of devastation has gone down with an alternate Hau'oli City with whatever happened to it - it's implied that it suffered from a nuclear meltdown, what with signs about a nuclear power plant being strewn around, and the radioactive material didn't just spread over Hau'oli, or even Alola - but the entire Pokemon world, including other regions such as Sinnoh and Johto. This is hinted at the fact that the guy with the hazmat suit (which resembles Guzzlord, for that matter) mentions about you coming back to the planet, which suggests the entire population of every region had to flee to another planet because it was getting so bad. What's worse, it wasn't even done with malicious intentions, which is what this sign says when I came across it during my stroll:
"...oli ...ity Ha.. 'Servi... ... ...ity's ...need...'"
That is a creepy sight to behold, when combined with the overall destruction, yellowing sky and distorted music, and what's worse is that you can pretty much make out what it's saying. Other sorry sights include the hole where you could do Poke Finder reduced to a wreck, and the broken display which gives off an oddly strange effect, not unlike that with the TV in the Old Chateau - because it actually still works. It also hits even harder when you realise that this is an Alola where the player didn't intervene to stop the UBs, and they were able to wreak havoc and destroy large parts of the region, quite possibly causing this nuclear meltdown.
Not gonna lie, when I caught Guzzlord I didn't head straight back to the altar like with the other Ultra Beasts, I decided to remain there a little longer and examine how far gone this place was. They sure did go all out with the last handheld Pokemon game...