(Not to be confused with Fanservice.)
The Degeneracy Generator was the standard power source for Buster Machines and other mecha up until the technology was purposely sealed between Top o Nerae! Gunbuster and Top o Nerae! 2: Diebuster, as it was humankind's use of degeneracy and warp technology that attracted the attention of the Space Monster race. The Degeneracy Generator plays an important role in both series.
The Degeneracy Generator is capable of generating a near limitless amount of energy, and is a key factor in warp technology. The Degeneracy Generators can easily power the weaponry of Buster Machines, allowing them to wield planetary-scale destructive force. While most Buster Machines are equipped with one Degeneracy Generator, the Gunbuster was equipped with two Degeneracy Generators as it was the combination of Buster Machines 1 and 2.