Core War

The Core War was a cataclysmic event that ocurred on Spherus Magna a very long time ago. The war was mainly contributed by the Element Lords and their supporting tribe members, as well as Toa and Matoran stowaways who were supposed to be constructing the Matoran Universe Robot.

BIONICLE: Universe
The Core War has a significant part in BIONICLE: Universe, and is first shown at the beginning of the film. Hundreds of various warriors are battling each other - but among all, Toa Tahu leads several other stowaway Toa and Matoran to the Matoran Universe - but they fail, and take shelter on a giant tree, along with various Glatorian, Agori and Toa Zeta Magnus. As earthquakes devastate the planet and split it into three pieces, an Energized Protodermis tidal wave erupts from the planet's core. As the tidal wave arrives to the tree Tahu and his crew are on, several Matoran and Agori fall to their deaths. Zeta Magnus, however, makes a heroic sacrifice to save the Matoran Blaze. Zeta is killed by the tidal wave himself, yet Blaze had been brought to safety.

After the Core War, all of the warriors had either been killed, trapped or had managed to retreat, and possibly make it to safety. Tahu and his surviving crew members joined together to attempt finding the Kanohi Ignika to resurrect their broken world, which was Zeta Magnus's wish.