This will be moving to PMwiki soon!
The battle story is my favorite Zoids continuity (along with the old UK comic and Fuzors), so I'm trying to do something for it...in wiki format. Rambling, informal wiki format. Expect it to be slow going, and forgive all the redlinks!
Told in a combination of fanbooks, leaflets, and bits of text on boxes, the battle story focuses on the conflict between several factions and the characters involved. While there's a lot of character overlap with the Chaotic Century anime, it's more a case of two different takes on things using a few similar elements and setup-bits—think comic!Fullmetal Alchemist versus the first anime.
For even more fun, those foundations are 80s marketing written by two different companies, leading to lots of continuity wibbles in the older bits that were later...mostly ironed out. Mostly :D.
I'm doing my best to keep this accurate, but everyone makes mistakes. Please let me know if you spot any errors!
Its natives made their Zoidy friends into combat mecha, the ones living on the Central Continent squabbling amongst themselves until being united into a republic by one Helic Muroa. Peace didn't last, because it wouldn't be much for action otherwise. Helic's two sons didn't get along for a multitude of reasons (including a lot of political unpleasantries and jerkassery on both sides), and not long after his death, Zenebas split off and formed his own empire.
After some years of conflict between Zenebas and Helic (the second), a human ship called the Globally 3 crash-landed, bringing technology to make Zoids nastier on both sides and spurring the conflict on further. This war formed most of the original Zoids line's story, dragging many characters into interesting and nasty fates.
Near the end of the war, a losing Zenebas turned again to help from Nyx and its ruler, Guylos—who betrayed him, absorbed the Empire army, and turned the last seven years of the old war into a Dark Army versus Helic Republic conflict. This had a more clear cut "good and evil" flavor to it than previous story, but when the toyline got canceled, in-story things finished with no victor. A comet collided with one of Zi's moons, raining destruction on the planet. 'Twas a bleak end for Zi, but perhaps fitting considering the old line's oft-tragic tone.
Cut ahead to the late 90s our time, 33 years later in Zi's time, and the models' revival meant Zi needed to return to war. The Republic, now headed by one Louise Elena Camford (Zenebas' daughter in disguise), faced conflict with the Guylos Empire again...as run by Günther Prozen. The fighting moved to the Western Continent (as crossing directly between Nyx and the Central Continent was made trickier now by magnetic storms), and eventually Nyx again as Guylos forces started to lose.
Prozen revealed himself as Zenebas' son, and the initial war as a ploy to get the Zenebas Empire back in power by weakening both sides. Mortally wounded, he destroyed his own Death Saurer to take out the Guylos capital and further throw things into chaos. His son, Wolff, overran the Republic capital (killing Camford in the process), and naively attempted to establish a better, nicer version of the Empire. It didn't work, and the conflict continued in guerrilla warfare before the Republic (having retreated for a time to the Eastern Continent) attacked to take back their capital in force.
Unlike his father and grandfather, Wolff eventually proved willing to let go of his rivalries when a battle with Ray Gregg led to his overclocked and damaged Energy Liger threatening the city and people around him. The final confrontation of factions ended with him joining forces with Ray to stop its explosion, presumably the first step to a peace that actually lasted. Zi's future after that is uncertain, but the Three Tigers story hints at a world where Zoids are used in sports combat and other explosive but constructive pursuits, and at a people who don't want anything to do with those who try bringing back the wars of old.