Overlord

The story of the Overlord begins with the mysterious alien energy-being and self-styled Decepticon god, Devil Z, who schemed to create the ultimate lifeform by merging Transformers and humans into one. Devil Z stole a collection of Transformer Transtectors from the G Nebula and brought them to Earth. Devil Z recruited two human beings, husband and wife Giga and Mega, and charged them with creating an army for him. Mega and Giga were both bonded to the largest Transtector, and together, they became the terrifying Overlord, serving as Devil Z's "Ambassador of Destruction" on Earth.

In this continuity, each of Overlord's two components are piloted by Giga and Mega, and are hence known as the Gigatank and the Megajet. As deadly as his "Chōkon Daemon Blast" lasers and "Chōkon Bolt Masher" grenade launcher are, Overlord has little need for projectile weapons: as a Godmaster, he is capable of manipulating Chōkon Power, and can even employ it to inhibit the regenerative abilities of other Godmasters.

(Source: TF Wiki)