The Black Impulse is the villainous organization from the Thunder Cross series. This mysterious alien organization is an ally of the Bacterians, and as such they use a very similar technology for their warships. The Black Impulse is controlled by Sprouts Layber, a computer located on their base. All of their machines are powered up by a orange crystal core, the same which also serves as the core of Sprouts Layber.
The Black Impusle have set it's sights on the human planet Haniamu IV, which they attacked with their armada. In response, the humans send the Blue Thunder M-45 and the prototype Red Thunder M-24 to fight them. After a initial defeat, the Black Impulse retreats, upgrading their forces for a new offensive. Three years later, they launch a new attack against Haniamu IV, who in turn sends again the Blue Thunder and Red Thunder. The two ships defeat the Black Impulse forces and destroy Sprouts Layber, thuns putting an end to their ambition.