Ultimate crossover event

Roland, the last gunslinger travelled down a silent, lonely road on the path of the beam towards the dark tower. His ka-tet was dead. His father was dead. Overall his past was dead. So now he just travelled. A lost soul on a quest. A quest of the ages. A quest to find the dark tower and save the universe from extinction...
The gunslinger looked up, and saw a strange floating green light up in the sky. Roland reflexes hadn't Dulles a-bit in his age, and he reached down to his gun, pulling it up and pointing it at the sky. The green light floated down towards Roland. He fired at it, five bullets hitting it, and bonking right off. Roland put his gun down, seeing that the green light was just a ring with light emanating off of it. He reached out and held the ring in his hand. All of a sudden, it spoke. "ROLAND OF MIDDLE EARTH, YOU HAVE BEEN CHOSEN TO WEILD THE GREEN POWER OF WILL AND BECOME A GREEN LANTERN." Spoke the ring in a strange robotic voice. Roland fired at the ring as it slipped onto his finger. All of a sudden Roland's clothes and body lit up green. His outfit staying mostly the same but now a dark green instead of the usual plain brown if it. A white symbol of a lantern was embedded in the chest of his suit. Without warning the ring flew him up into the air. A portal appeared out of the ring and they flew into it. Roland struggled to free himself, but the ring is in control of where he goes now. He finds himself flying through space at faster than light speeds. Roland realizes that he is not in control or power here, and stops struggling. He stares out blankly at the strange planets passing him by. He looks closely. He remembered what Cort had taught him years ago, to look at something differently and not see it at face value. His gunslinger eyes saw, and saw very closely. He saw every planet they passed by, every inch of every one. His sight seemed to somehow be enhanced by the ring. The gunslinger was no longer in Middle world any more or even in that same universe. He realized that he was in the "DC universe" a boy he once knew had told him about. The boy had told him that "DC" wasn't real but Roland realized now that it was just as real as his world was. He saw the Superman and the Batman the boy had talked about. Roland stopped looking at the planets and looked to see what was in front of him. A green planet with a strange white lantern in front of it was in front of him. Finally he landed on the planet and was approached by a strange green man who the boy had called "Green Lantern". Roland reaches down pulled out his guns and pointed them at the green lantern.
"There's no need for that, Roland Deschain, we are all friends here, ok?" Calmed the green lantern.
Roland lowered his guns (still ready to pull them back out at any moment) and spoke.
"What is the meaning of this? Why do you bring me to this strange universe and interrupt my quest?" Roland demanded to know.
The green lantern smiled.
"First of all can I clarify something? We did not interrupt your quest you are still on the path of the beam and you are still going towards the tower. But ka has brought you here, to us, so I ask of you to please stay here and let us explain the purpose of your sudden kidnapping."
Roland nodded.
"Speak."
And the green lantern spoke...