If you're looking for manga similar to Transformers: Energon Special, you might like these titles.
On a primitive planet with fauna similar to Terran dinosaurs and Ice Age critters, one of the angolmois energy capsules spread by the explosion of the Nemesis has affected the locals. A gang of evil dinosaurs have been transformed into Destrons, and a battered Lioconvoy is too injured to stop them. So he transfers his energy into a mammoth named Big, charging him with continuing the good fight.
All across the universe, the forces of the Maximals and Predacons are at war... and the Maximals are on the losing end! At the central headquarters of their army, a Convoy receives report after disastrous report from the battlefield, and thinks of the small team of warriors led by Lio Convoy, fighting to keep the Angolmois energy of the planet Gaea out of the hands of Galvatron...
In the year 3195, there was a war between an army of robots and the humans. When Shaian, a sentient combat armor, lost his companion in battle, he shut down until his internal systems spotted a new human. It's now almost a 1000 years later, and Shaian's greatest enemy is still alive and doing battle in Brazil. With a new friend`s help, Shaian may be able to stop this evil force before another war rages over the continent.
Ryoma Nagare, Hayato Jin, and Prof. Saotome pilot three specially designed combat jets, which can be combined together in different forms to form three different kinds of giant robots, Getter-1 (used for aerial combat), Getter-2 (for land-based conflicts), and Getter-3 (for undersea battles). They were assembled by Prof. Saotome and became Earth's first line of defense against the Dinosaur Empire, which is a civilization of reptile-like humanoids, who evolved from the now-extinct dinosaurs that roamed the earth millions of years ago.
An old Hayato leads the Saotome Research Facility, which has developed the Getter Robo Hien to combat a new force which threatens the Earth: large plantlike monsters.
While Professor Saotome completes his masterpiece, the Shin Getter Robo, a strange object enters the Earth's atmosphere. Hayato, in control of the lab while Saotome obsessively works, orders Getter Robo and Getter Robo G to launch and destroy the object before it impacts.