What don't you understand? There was a "room" above him and he levelled up offscreen, which started him zipping.
The location is prime because of the warp room just to the left, and he still has to kill flying armour to have access to the room. (Well, not entirely true, but that path requires double-jumping and a lot more time.)
Apparently, the room doesn't have to be a screen transition, as long as you can be offscreen with a room above you.
And about the only way this could be any faster is if the level-up with the Warg could trigger: the glitch, the flag for Flying Armor to be dead, the flag for Menace's death, the Abyss waypoint, and the Black Panther soul faster than killing Flying Armor and glitching two rooms left, but I suspect that MP is too low at that point to manage it.
I am still the wizard that did it.
"On my business card, I am a corporate president. In my mind, I am a game developer. But in my heart, I am a gamer." -- Satoru Iwata
<scrimpy> at least I now know where every map, energy and save room in this game is
