Tried some pseudo anime thingy. If this was a real thing it would obviously be some high budget OVA shit. 

"The Zeus is armed with a Thunderbolt graviton rifle, which fires a condensed energy beam that is highly sensitive to gravitional changes.
This allows the beam to be fired in a curved or straight line depending on the beam's acceleration, and the position and altitude of the Zeus above the Earth. 
There are war stories and rumors told of legendary marksmen that could hit targets that were located on the opposite side of the planet with the mere knowledge of the their targets' coordinates."

This guy would belong in the same universe as this one: 
EW-02 Hekaton by emersontung

More robots: 
TankHead Mk. II by emersontungTankHead by emersontungSamurai - Mechanical Samurai Tokugawa Unit by emersontungSamurai - Mechanical Samurai Nobunaga Unit by emersontung