Vector Prime, on a side quest to the central Cybertron animated series storyline. Toys A small number of Transformers: Energon Built to Rule sets had a limited, test market release, and the structure of the Trans-Skeleton was changed for the Energon'' characters, to a much more solid skeleton with larger, blockier limbs. This led to much more solid, stable and sturdy-looking robot modes, but the entire line performed poorly, so it was dropped in its entirety in 2004. References External links Takara page 2004 anime television series debuts 2004 Japanese television series endings Japanese children's animated action television series Japanese children's animated space adventure television series Japanese children's animated science fantasy television series Japanese children's animated superhero television series Actas Adventure anime and manga Computer-animated television series Mecha anime and manga Japanese television series based on American television series Television shows set in the United States Television series set in the 2020s Toonami Energon Energon TV Tokyo original programming