I was thinking about trying it solo too. How are you doing the Abyss? I can never do the rock jump with my Warlock.
I tried doing the rock jump but i feel the timing is too hard to get right.
So I am doing it like this basically:
run to first lamp, survive until weight of darkness is down to 0, jump onto the lamp, wait for health to regen, kill cursed thralls from ontop the lamp.
jump to the next lamp, throw a solar grenade, which kills 90% of the thralls, wait, jump onto the lamp, wait till a few seconds before it explodes to give the grenade time to reload, etc until the bridge-plate, there i just get on the rock, snipe the ogre and wait,
took me an hour or so to get it the first time, now i can do it 75% of the time, i'll post a video.