Kara and Mon both end up going through a black hole that takes them to the 31st century. In this time, the Earth is deeply divided and in dire need of superhero leadership. Kara, Mon, and Brainiac 5 recruit a diverse group of characters to become the Vindicator Corps. A spin-off sequel to Adventures of Supergirl.
While stranded on Argo City, Mon-El had told Winn how he intended to stay with the woman he loved. And with his full heart, he intended to keep that promise. However, with the returned threat of Brainiac 1, he was needed with the legion even more. Thus, he returns to his own timeline to help his friends fight against the sentient android. Though thankfully he's not alone.
Mon-El is captain of the USS Nemo, Earth's flagship in the 31st century. Along for the ride is his faithful crew of aliens and humans including Imra Ardeen (Saturn Girl) and Brainiac 5. On their voyages, the USS Nemo crew explore new worlds, discover superheroes, and form alliances that will lead to the Galactic Federation of Planets. Parody of Star Trek Enterprise.