i agree that the storyline could revolve around energon. after all, there are many storylines of the decepticons stealing energy from Earth’s resources including ruby crystals, niagra falls, and crude oil.
decepticons have also been known to take energy from extra terrestrial sources including cybertron and vector sigma itself.
some other storylines up for grab include golden age, headmasters, minicons, etc.
spores or quintessons might be a good concept…something that involves the autobots and decepticons coming together to fight a greater threat