A 12-issue series, the series expanded the original G1 mythos from the small war on Earth and Cybertron to enclose the whole of the Galaxy that was fast being altered into a likeness of Cybertron itself by the Cybertronian Empire, a race of later generation Transformers that evolved while the earthbound Autobots and Decepticons were deactivated. The events of this series were actually set in motion with a crossover from the G.I. Joe comic books #138–142, in 1993. Megatron returns in his new tank body to reclaim his leadership from Bludgeon and by the end of the series joins with Optimus Prime to fight against the G2 Decepticons and their genetic offshoot, the Swarm. The series ended with an epic battle between the "Generation 1" Transformers, the Cybertronians and the Swarm. It also introduces the Liege Maximo. However, the series was cancelled with issue #12 due to low sales, forcing a quick conclusion to the series' various plot threads. Outside of the 12 issue series, Marvel published a free 8 page comic that was given away at various stores selling the G2 toyline called "The Transformers Generation 2: Halloween Special Edition" in 1993.