Ed comes back to see a (nearly) post-apocalyptic world instead of the peaceful world that was supposed to have been saved. Since this was the first other world he entered, his past banishment here was not due to his own instigation, but his lack of power and useful skills. So even if he didn't get banished, he couldn't have prevented the hero's defeat and death if he stayed there for 5 years instead of ~1.
For a moment I was afraid Tia was in captivity with the demon army, but it turns out she's just living peacefully away from trouble. I assume she's going to be the female lead of this story, and she'll somehow end up world-hopping with him. Somehow, I doubt that he'll be able to open the door to world 000 with just this visit. I feel that he's going to be forced to visit each world one more time and that means he'll be doing 200 rounds total.