"Duet" is the seventeenth episode of the third season of The CW television series, "The Flash", which aired on March 21, 2017, the  story begins at the end of the "Supergirl" episode ,"Star-Crossed" on March 20, 2017, which sees Kara Danvers / Supergirl (Benoist) being put in a coma by Music Meister, with who (Chris Wood), Lar Gand, and alternatively as Valor and M'Onel), is a fictional superhero appearing in American comic books published by DC Comics, commonly in association with the Legion of Super-Heroes, Superboy, and Superman, is primarily known as who?
Lar Gand Lar Gand, known primarily as Mon-El (and alternatively as Valor and M'Onel), is a fictional superhero appearing in American comic books published by DC Comics, commonly in association with the Legion of Super-Heroes, Superboy, and Superman. The character has been reinterpreted over the years, but in all versions, he serves as a hero with abilities similar to those of Superman, sometimes serving as a substitute for him.
Our Worlds at War "Our Worlds at War" was a comic book storyline, published by DC Comics in mid-2001. OWAW was a crossover storyline that spanned several different books, including several books starring Batman, Superman and Wonder Woman, The Flash, Green Lantern, and a number of supporting characters and books. Creators involved in the crossover included writers Jeph Loeb, Joe Casey, Mark Schultz, Joe Kelly, Phil Jimenez, and Peter David, and artists that included Mike Wieringo, Ed McGuinness, Doug Mahnke, Ron Garney, and Leonard Kirk.