Eye Of The Storm Quest

I have a couple of questions regarding this quest. I died while entering the ritual chamber because it was too dark and I had no idea where I was going. Is there a way for me to skip the buggy parkour that cuts my health in half each time I fall, or do I have to do it all over again?
Also, are brightness mods like gammabright allowed? I get that the gloomy vibe of dungeons and caves looks good, but it's not going to be immersive if I can't see where I'm going.