Robotmasters

Set in the years 2004–2005 of the Japanese Generation 1 continuity, it tells the tale of a conflict between the Cybertrons and Destrons in which a set of dimensional fissures known as the Blastizone brings forth characters from across time and space to the present day on Earth, serving as a big crossover event between Generation 1, Beast Wars, Victory, Beast Wars II, and more, in honor of the Transformers brand's 20th anniversary.

The series was published online through Takara's official website from 2004 to 2005, for a total of thirteen chapters. Each consisted of two pages and accompanying prose that expanded the comics' story. Being the longest-running of the Robotmasters fiction, the online chapters told the majority of the series's story and was the only one to see it through to a proper conclusion. Additionally, two physical comics, each four pages at length, were also published in catalogs packaged with the Robotmasters toys, and served as complementary in-between chapters to the online comic.

(Source: TFWiki, edited)