WARNING: HUGE DIEBUSTER SPOILERS ON THIS PAGE. Edit
Buster Machine 7 is Nono's true form, an ancient Buster Machine that possesses the ability to control the Buster Legion (what humanity calls "Space Monsters" at that point) and utilizes the lost technology of degeneracy generators to enable warping. She first appears in episode 4 of Top o Nerae! 2: Diebuster.
Buster Machine 7 is a version of Nono dressed in white and red with missile launchers coming out of the sides of her legs. While in this form, Nono's hair changes from pink to orange.
Buster Machine 7 wields incomprehensibly powerful weaponry by current standards. As the technology used to construct her was retired after her construction and warp technology sealed away along with her (so that humanity could never leave the solar system), Buster Machine 7 is the most powerful Buster Machine to ever exist. Her degeneracy generator, which forms her heart, enables energy and ordnance output on a heretofore unseen scale, allowing her to fire nearly limitless Buster Missiles from the missile launchers in her legs and unleash a Buster Beam powerful enough to cleave a planetoid-sized Space Monster in half. In episodes 5 and 6, Nono uses her abilities as Buster Machine 7 to form the Buster Legion into a Planet-sized shell, with possibly no limit to size, known as the Diebuster. In this form, her body is pure red and orange, and her face is adorned with a pair of sunglasses. She utilizes this form to attempt to stop Buster Machine Douze-Mille, piloted by Lal'C, from ramming Earth into the final Space Monster.