Destroyer actually refers to the evil entity that possesses the combined bodies of the Builders. The act of combining creates a massive energy surge as all the Builders energy cells unite. This surge attracts malicious codes waiting in the ether, who are too large and powerful to be downloaded into regular Bot bodies. One such code is the Destroyer. for some reason Destroyer favours the Builders and it is only Destroyer who has ever managed to do so. Democracy Bot experts suppose that their is some additional link between Builder code and the Destroyer code which helps facilitate the temporary Destroyer download but as computers are still quite new in the Democracy this is so far only a theory. Like its namesake, Destroyer is a code that hungers for destruction. Whole Democracy cities have been crushed underneath Destroyers heel and fist. He is also personally responsible for the destruction of a score of Valiant first incarnations.
Once the energy bond between the Builders is broken, the energy levels capable of sustaining the Destroyer’s code is no longer stable and the Builders collapse. Destroyer’s code returns to the ether where it awaits a new rampage of destruction when the Builders combine again.