Reverse-Flash and Damien Darhk have started the Legion of Doom.
Obsidian, played by Lance Henriksen, is confirmed to be the son of Alan Scott, the original Green Lantern.
In the comics Obsidian was Todd Rice, twin brother to the female superhero Jade. They were the children of the Golden Age Green Lantern Alan Scott.
Martin makes a reference to dinner reservations with his wife at "L'Auberge." In the Washington DC area, that's most likely a reference to L'Auberge Chez François, a DC-area restaurant with a long-standing reputation as one of the most romantic restaurants in the region.