Ran through the cast to make a quick list of who Dormammu can get easy double relaunches off of in the corner. Way to do the relaunch is as simple as dashing up to them and laying down a flame carpet. If you want to do 2 launches off one carpet, launch them after the 3rd bounce, then you can re-launch them when they land on the carpet again. Or you can launch them after the 5th bounce, and lay down another carpet to relaunch.
This is just a short simple list for people who might be wondering who it works on.
For all other characters, if you do a flame carpet in the corner they will hit it once, then go into knockdown, and if they don’t roll out they will be forced to block the rest of the carpet. A nice thing you can do with this is jump up and do a quick dashdown L which will catch them if they don’t switch from low to high block in time.
Arthur - Arthur is a bit special in that he bounces a lot faster, it is possible to do 2 launches off a single carpet but it is much easier to just let him bounce 5 times then do a new carpet.