In a recent 'A R R O W' episode, Doctor Arthur Light/Doctor Light was mentioned to be working on a project in S.T.A.R. Labs before being fired cause of being a psycho. Soon after he was mentioned, a weapon that can manipulate light by causing it to become a energy blast was used. When Harold Jordan appears, he'll become Green Lantern by use of that technology's advanced form; a light manipulation suit. But, they'll put together the reason Hal's use for this tech causes green light. They could reveal that it's being energized by a ring shaped device that was found on the dead body of someone who crashed landed in a California desert and that the ring device couldn't become utilized by other volunteers until Ferris Air test pilot, Hal Jordan volunteers after losing his job at Ferris Air to do exciting things again. If WB chooses for connecting 'Arrow'/'Flash'/'Hourman' with 'Man of Steel'/'Superman-Batman'/'Justice League' etc, Christina Wren can appear in Arrow as Carol "Carrie" Ferris coming to California.