I completed DC run on second day of season completely blind with another 3 blind random players. I haven’t watch any YT at the time as I thought I was doing quest to unlock it. We did it after try and errors, it is not difficult to get one of three of your team mate figure out himself that he should step on a patch of floor with glowing light. Wait outside a door, kill a fat monster and then pick up the triangle inside. Or teleport to another dimension, do some chore and return.