Belial Revolt

"Belial! Destroy it all! Terminate the Ultramen and destroy the Land of Light!"

- Alien Rayblood.

Belial Revolt (ベリアルの乱) was the second invasion attempt on the Land of Light in Mega Monster Battle: Ultra Galaxy Legends The Movie. The instigator was revealed to be none other than one of their own kin, Ultraman Belial as a revenge for his banishment.

Mega Monster Battle: Ultra Galaxy Legends The Movie
Shortly after the Great Ultra War, Belial's jealousy for Ken's popularity and inspiration in Alien Empera led to his banishment from the Land of Light after a failed attempt to harness the power of the Plasma Spark. During that time, Alien Rayblood approach him and convert Belial into a Reionics.

With the use of Giga Battle Nizer, Belial led an army of 100 monsters to invade the Land of Light under Rayblood's instruction. Seeing his old comrades Zoffy, Marie and Ken, he charged and almost killed them until Ultraman King appeared as he imprisoned Belial within the Space Prison. The Giga Battle Nizer was sealed within the Valley of the Flames underneath the Monster Graveyard and guarded by an EX Zetton.

Trivia

 * Ultraman King was stated not to be seen by others until Ultraman Leo's era on Earth. This may be a continuity error or the fact that during his appearance on Belial Revolt, he was only seen by Zoffy, Ken and Marie (who would become important figures in the Land of Light), thus the rest of the Land of Light inhabitants failed to notice his presence.