I advise those of you who haven't watched Black Heaven's story videos and/or don't know the actual storyline behind it NOT to read this, as it contains spoilers.
Spoiler
So, I wonder how could Nexon's logic think it would make sense to create a dungeon inside an "exploded" (I remind you of that short anime clip) Mechanical Airship, making its map backgrounds and tiles look like it was just "slightly damaged". I mean, the maps of Destroyed Black Heaven look like the ship never exploded at all. Look, if it had REALLY exploded you shouldn't even be able to enter it or find ANYTHING working in there. Instead, I see many cogs still moving and other mechanical stuff working, even if they made it look like it's in bad conditions.
I'm likely using too much logic for a game as usual, but I still think it should make sense according to the storyline. They likely wanted to make it look as if Black Heaven was nearly indestructible, therefore its 'fall' only damaged it slightly, but I think this was more of a way to make it still accessible by players without having to re-do the whole questline, AND a way to make a "normal Lotus" boss.
I really loved the effort they put in all this, from the story to the maps and their beautiful soundtracks, but I think they should've made Lotus only killable once. I know, that would suck, but it surely would make more sense than all this. How did Lotus resurrect himself after you killed him? How comes those robots are still working? What is their power source? Storyline-wise, that can't be explained in any way, unless there's something I'm not aware of.
It's just a little sad when you see a story which makes sense and works so well, and then they sort of 'ruin' it with mistakes like these.