spoiler

The twist I'm talking about is with the Tiger Beast. They show that she helps Kururu, but don't say why or how Kururu managed to talk her into it. Then the Tiger Beast just stands there like a dumbass and lets the hotel collapse on her for no reason. And she isn't glowing, which again, isn't explained. Afterwards, no one is like, "Hey, where's the Beast that we owe our lives to?" It's just completely forgotten about.
Then they just leave the whole plot point that hey, there's a giant volatile Cerulean-spawning volcano and a Cerulean the size of a yacht parked right outside the hotel. Given how much time S2 spends with episodic tangents that could have been edited out, they could easily have projected how long it would take to wrap up the arc before the end of the season. They knew how many episodes they had to work with (I assume), so it shouldn't have been that hard to fit a complete plot into one season.