Kamen Rider Saber ＋ Kikai Sentai Zenkaiger: Superhero Senki

Touma, Yuri and Mei somehow ended up in the world of Zenkaiger while the Zenkaigers, minus Juran, ended up in the world of Kamen Rider Saber. The reason for their swap is due to a man who wishes to ride 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? (source: tokusatsu.fandom.com)