Used to do this a lot when the raid was still relevant and I was looking for "secrets". They must have changed something because before I would run through the abyss, get to the bridge, and then start killing everything. It would only spawn 89 enemies every time. Seriously. 6 ogres, 8 Knights, and the rest thrall. After that I would be free to walk back and explore unbothered by enemies. Each time, at the wipe screen it would be 89 kills 1 death. I used to have fun with this and will have to try it again if it spawns unlimited enemies now.