Iron Lantern is the combination of Tony Stark aka Iron Man, and Hal Jordan, aka the Green Lantern. He appears in Iron Lantern #1 in 1997 as a part of Marvel and DC's Amalgam Universe.
Hal Stark is a billionaire and founder of Stark Air-Crafts. Hal was working on a flight simulator when the device suddenly took off with Hal in it.
Stark discovered that the flight simulator was being drawn to a distant planet. Hal crashed landed on the planet yards away from alien space craft wreckage. Hal was badly injured with shards of metal stuck in his chest, Hal decided to make his way over to the ship in hope of survival.
Stark stumbled on to the ship where he found a dying alien called Rhomann Sur. Rhomann Sur was sent by Oa, the Living Planet to deliver a message to Hal but before Rhomann could give Hal the message he died from his injuries.
Hal realizing he was dying as well, Hal using all of his genius and engineering skills made a high-tech suit made from parts of the alien ship the suit was powered by a mysterious battery witch reminded Hal of a lantern [the super powered battery was the item that Rhomann was meant to deliver to Hal from Oa.
Not only keeping Hal alive the suit gave Hal amazing powers such as flight, super strength, super speed, time travel, energy manipulation and energy projection.
On his way out of the wreckage Hal was attacked by the alien who shot Rhomann’s ship and was after Hal super powered battery. The alien was heavily armed but was no match for Hal, Hal easily beat the alien with his new founded powers. After the battle Hal decided to use his powers for good, on his way back to Earth Hal took the name Iron Lantern.