Wasted potential - the Pokemon. This was literally the first chance for them to make a truly antagonistic Pokemon and they blew it. The entire story revolves around people wanting to stop it from ever entering their world and destroying. Eventually it does and even takes over the box legendary for its own selfish reasons. Instead of giving up it flees and even after confronting it a second time it absorbs the entirety of the box legendary in order to regain its original power, even havin some ultra energy buff it. Fine and all, you beat it and save all the trapped light inside it, though still leaving Ultra Megalopolis without any. Now this is where it should have been left at, instead of crashing into Mount Lanakila it should have retreated into some rare realm in Ultra Space and have been crashed down there and even after catching it further imply that it is cruel. And what do they do instead? Tell you that it was once good, gave away free light until people started to abuse its powers and strip it from all light turning it into a ruthless killing machine that sucks away all light. Another "misunderstood" legendary. Fucking wasted.