First off, how are you not sure about Sawasbuck's nature? Second, no EVs or role given? How are we supposed to know what each pokemon's role is? And, you have a massive ice weakness and no ice resists. I'd recommend Volcarona as an ice counter. All Hydreigon's abilities are levitate, not hustle. Additionally, please explain this; "Garchomp...Nature: jolly/adamant" Finally, I believe story mode teams are not RMT eligible.
PS: Sorry for the wall of text.