I just beat the Behemoth and he's actually pretty easy. Just keep launching him when he starts flashing yellow.
I'm starting to get used to the battle system and it's becoming a little bit more manageable. It's not very fun yet, but I think it's because of the lack of options in the beginning of the game. I still want some kind of wait mode, though, and I still think the HP numbers are a bit too small. And I hope there will be an option to stop the camera from zooming in every time you stop moving.