Lamplighter, referenced throughout the first season but only seen for the first time in Season 2 Episode 5, was previously in The Seven, but was replaced by Starlight in Season 1 for reasons we do not know. We do know that CIA Agent Grace Mallory has said that Lamplighter killed her family, and that he's now got some sort of arrangement happening with Stormfront, and we don't feel good about it.
His Justice League equivalent is said to be Green Lantern, and with the fire aspect he's got a little bit of Johnny Blaze from The Fantastic Four in him as well. A little easter egg is that he's played by Shawn Ashmore, who is best known for playing Bobby/Iceman in the X-Men movies. Ice and Fire. But Jon Snow, he is not.
