Hero Is Overpowered but Overly Cautious, Vol. 6 (light novel)

The invasion of a malevolent deity has brought the spirit world to its knees! Rista falls unconscious amid the turmoil, and when she next opens her eyes, she finds herself in a distorted version of Gaeabrande. Here, humans and demons have joined forces against a much greater foe, forging alliances as bizarre as Rosalie Roseguard and Chaos Machina! Nothing makes sense anymore, so why not double down on the madness? In order to save the spirit world, Seiya is summoned once again, and this time, his base of operations will be...the underworld!