The Dork Knight himself.
Quote from RoboSparkle:
It's the new area transfer that gives it to you in City. The only cutscene trigger in asylum would be Ivy, so if you can get over that ravine w/o Line Launcher that's a possibility (and if you can do that do you need to even fight the titans?)
The only way I can think of to get over that pit to talk to Ivy would be to fall into the pit and somehow trick the game into thinking you jumped from the other side when you save yourself. I've never seen anything along the walls you can get stuck on or stand on.