Crypt Cosmic Circus is the Yellow Legion that is led by the Yellow King, Yellow Radio. They control Taito, Arakawa, and Adachi, including Akihabara areas.
It was one of the main seven legions that were created after seven Brain Burst Linkers had reached level nine becoming a king and gained their own territories
Yellow Radio appears along with his legion in the neutral field to kill the Red King, Scarlet Rain who is currently trying to stop Chrome Disaster with the help of Nega Nebulus.
The Yellow Legion starts to open fire on them. Silver Crow activated his wings, but Yellow Radio used his Silly-Go Round move on him to confuse him. When Cyan Pile was destroyed, Rain activated her Immobile Fortress. Yellow Radio encouraged his legion not to be afraid, ordering them to tear the fortress apart. Despite the Red King's overwhelming firepower and assistance from Silver Crow, they were just two against a whole army, which slowly wore them down.
Chrome Disaster later shows up and pierced Its weapon into Yellow Radio's abdomen. Initially being shocked, then It attacks some of the Yellow Legion then Yellow Radio and the Yellow Legion retreated