Kamen Rider Saber + Kikai Sentai Zenkaiger: Super Hero Senki (2021)

Touma, Yuri and Mei somehow ended up in the World of Zenkaiger while the Zenkaigers, except Juran, ended up in the World of Saber. The reason for their swap is due to a man who wishes to rid the world of heroes. How does a male, teenaged artist tie into this? And why are they send into different stories with previous Kamen Riders and Super Sentai Teams?