Sometime after Belial regained the Giga Battle Nizer after killing Reibatos, Belial orchestrated the Omega Armageddon alongside Kei Fukuide, the Darkness Five and his new army called Terror The Belial (テラー・ザ・ベリアル Terā Za Beriaru) in a heated battle with the Ultra Warriors from the Land of Light at the World of Side Space, which held the fate of the universe at stake. During the battle, Ultraman Hikari created the Ultra Capsules to preserve the powers of the Ultra Warriors, hoping it could change the outcome of the battle. The battle also caused the destruction or severe damage to many planets in the universe, some of the most notable ones being the home world of the Alien Shadow race - who became convinced that they would not be safe if they kept only one home world, causing them to begin searching for new planets to colonize - Planet Sturm and Earth. After defeating Zero on Earth, Belial detonated the Super-dimensional Eradication Bomb which triggered the Crisis Impact, and the aftermath events.
- Main article: Crisis Impact
The presence of the Ultra Warriors during the said battle had became a popular legend, with records of their existence being mysteriously lost and the memories of them slowly fading from the collective consciousness of humanity.
- The fan theory of Belial having an army during this conflict was confirmed due to the presence of Kei Fukuide, the Darkness Five and most importantly with the backstory of Dada's Legionoid that he salvaged from Belial's forces. This new army was called the Terror The Belial. This theory was mentioned by Zero when talking about the invasion of Alien Shadow Zena's homeworld, which also cause him to initially join AIB in hopes of restoring Planet Shadow's glory.