Ultra Galaxy Mega Monster Battle: Never Ending Odyssey is the second season and the 25th entry in Tsuburaya Productions' long-running Ultra Series. After the events of the last series, ZAP Spacy finds itself under attack by the Reionyx Hunters, members of the Pedan species and the creators of the original King Joe Black, that seek to exterminate all reionyx in the universe. The story takes place on Planet Hammer where ZAP Spacy finds itself battling the Reionyx, Reionyx Hunters, and the originator of the Reionyx, Reiblood.