For summary some post series info.
Killbus the elder brother of Evolt, in the New World Kamen Rider Cross-Z movie can cause an universal destruction using one panel of the Pandora Box fuel by Evolt energy.
Basically Evolt had the energy to cause a Big Bang and with one panel of the Pandora Box him someone can generate that energy. Killbus is stronger than Evolt(said by Evolt himself) and the main villain of New World Grease movie absorb the white panel of Pandora Box to made himself stronger and was defeat by Perfect Kingdom Grease. Also was the fact that White Panel and Black Panel alone can merge 2 universe in 1 and create the New World.