The Dark Heart is an antimatter weapon developed by the GoBot known only as the Evil One.
Challenge of the GoBots cartoon
After the disappearance of the Master Renegade following the first Renegade Revolt chaos reigned on GoBotron. The Evil One was one of several fighting for control of the planet, harnessing stellar energy to create the Dark Heart. He used it to unleash a wave of anti-matter on the planet, though ultimately GoBotron was saved. The Evil One fled with the Dark Heart, landing on Earth. Years later with his end near he devised a hiding place for the Dark Heart so someone worthy (by the Evil One's standards) could take up his legacy, with a pyramid being built over his tomb. Some 6000 years later a scout drone from the Evil One's ship was discovered by Doctor Cunningham during an archaeological dig in what was now Ecuador. After contacting General Newcastle with his news Cunningham found out from Scooter that the technology was GoBotic, and might be related to ancient legends about the Evil One and his Dark Heart weapon. Scooter, A.J. Foster and Nick Burns were sent to help the investigation; however, Cunningham was secretly in league with the Renegades and contacted Cy-Kill about the find. In the resulting face-off the craft - just a drone - was destroyed. Cunningham's cover stayed intact and after Matt Hunter deduced the Evil One's craft was hidden by the Nazca Lines in Peru he once again passed the news on to Cy-Kill. As such the Renegade leader arrived in Peru as they discovered the Dark Heart, a hugely powerful antimatter weapon, disguised as a sphinx. Cunningham revealed his betrayal by handing it over to Cy-Kill; Leader-1 was successful in talking Cy-Kill down from using the device. However, Cunningham had no such scruples and triggered the Dark Heart in an attempt to end existence. It took the combined energy of Leader-1, Turbo, Cy-Kill, Cop-Tur and Crasher to contain the antimatter wave but they were ultimately successful. The exhausted Renegades retreated and the Guardians took the Dark Heart to a safe hiding place - in plain sight in a museum, back in its' sphinx guise. In Search of Ancient GoBonauts