In Transformers: Dark of the Moon, Megatron, Starscream, Soundwave, Shockwave, Barricade, Laserbeak, the Driller, Sentinel Prime and the other protoforms all die, in addition to Cybertron being destroyed.
If there is a Transformers 4, where do we go from there, in terms of Decepticons and other enemies?
I think it'd be easy to explain that there are Decepticons scattered across the galaxy, much like Autobots, and bring in a new team or something. Maybe modified by Unicron into near-invencibility, with Megatron being reformated into Galvatron.
I have some idea here
I think it would happen like in Energon another enemy appear Alpha Q and Unicron too and as u know in Energon Alpha Q could bring a dead bot back to life and he revive Meg and starscream, Megatron come back to life and change his name to Galvatron
And on Autobot, Omega Supreme will help us defeat Unicron