Since the A-list heroes of the Justice League seem to be almost universally off-limits, Arrow has had a lot of success pulling from the lesser-known Justice Society of America. One of that teams marquee members, who would fit right in with the darkness of Arrow, is Doctor Mid-Nite. Somewhat like Daredevil before he was cool, Mid-Nite is blind in the light but able to see in darkness. His combat revolves around a tactical approach and stealth strikes. He also offers an extremely useful function in that hes a trained physician, who's known for patching up other superheroes. This role could easily help to explain how the swift returns of any banged-up heroes in the future. And though Mid-Nite is traditionally depicted as the Scandinavian Pieter Anton Cross, they could use the character to add some diversity to the cast by instead adapting the younger, female Beth Chapel version of the character.