Dear, Vector Prime. Is there dimension in which the Astrotrain-built train unit in “Triple Takeover” became Transformer?
Dear Train Tracker,
Not those specific trains, but Astrotrain never abandoned his plans for an army of locomotives. In fact he became convinced that his plan had only failed as a result of the shoddy construction of the trains in question, and decided that only the best of trains would be worthy of becoming his new Astroforce.
Invading Shibuya Manufacturing, he took many of the workers hostage, as well as their state-of-the-art prototype bullet trains. When the Autobots became involved, he offered to release his hostages—in return for the Matrix of Leadership. Seeing no choice—for Astrotrain had turned the factory into a veritable fortress—Optimus handed it over. Surprisingly, Astrotrain kept his word, letting the humans go free.
As the Autobots worried over what he might have in store for them, Astrotrain used the Matrix to bring his new Astroforce to life. His "sons" as he named him were easily excitable, especially when they learned about the Japan's rail system, and although he tried to convince them of the Decepticon goals of conquest, the Astroforce were far more interested in racing each other, and human trains.
These races led to a chase, as Astrotrain and the Autobots tried to keep up with the speeding Astroforce. The havoc this caused even alerted the Decepticons back on the Victory, and Megatron became interested in these new Transformers, leaving the base to recruit them to the Decepticon cause.
The Astroforce were almost convinced to join the Decepticons, as Megatron promised that the Constructicons would build larger, and ever greater railways for them to race along. In comparison, Optimus Prime pointed out the devastation their antics had caused, reprimanding them for the danger they had put humanity in.
The Astroforce were unsure why they should care about humanity, until Astrotrain accidentally revealed that he'd only brought them to life by putting human lives in danger. Realising they owed their existence, however indirectly to humans, they decided Optimus was right. They refused Megatron's offer and apologised.
Megatron wasn't about to give up, and commanded the Constructicons form Devastator to destroy the rebellious Transformers; not wishing to see his "sons" destroyed, Astrotrain revealed to them that they had their own combined mode—the powerful robot known as Grandliner.
Grandliner drove off Devastator, sending Megatron fleeing for his life, and thanked Astrotrain for their creation—but refused his offer for them to come with him. For they had to undo the damage they had caused, and pledged themselves to defend Japan from all threats—even their own father.