When he was on the Redakai council, Lokar was intrigued by the dark side of Kairu and found a way to separate the good Kairu from the bad Kairu by giving up his soul. However, he was discovered and exiled by the Redakai council, which was headed by Master Boaddai at that time. However, he perfected the Black Kairu so its effects only affected Master Boaddai.
It has horrible effects on the environment, causing lightning storms, twisters, crop destruction, as well as causing land to become barren. It produces shadow versions of monsters (such as Bruteron from Bruticon), with several side effects such as the magma that appears on it. It can make monsters go out of control and allows fusions to be formed, such as Wendrax Fangax and Neurax combine to form Hydrax. Bruteron is also the fusion of a magma minster with Dark Bruticon. It also produces shadow versions of attacks and monsters, such as Dark Sword, a shadow version of Plasma Sword, Dark Root, a version of a plant-like ordinary monster and Dark Metanoid in Ky's dreams. It can force a personality to be negative like it does in Shadow Ekayon, where it turns Ekayon and Ky evil. It also devours Lokar's soul. So far only Lokar and Maya have fully mastered it.
Shadow Kairu appeared in Black Kairu, Gold Metanoid.
It appears throughout season 2.
- Since there are two types of Kairu, it somewhat references Ying and Yang.