After desperately refreshing a couple of times searching for the '666' account, the background of YouTube entirely changed into a fleshy, meat-like tissue composed of barnacle-looking "eyeballs."
One last refresh, and you're finally here, the domain of The Username:666. Barely even resembles the YouTube domain anymore due to how corrupted and rotten it is.
Most of the videos shown on her channel were mostly depicted as carnal, showing distorted imagery of fetus dolls spinning their heads, a swirled utereus and a moving framed imagery in red showcasing distorted depictions of women, babies, other body parts (such as hands, legs, etc), mechanic objects, plants and insects, indicating possible use of symbolism.
While you continue exploring her decrepit domain, you feel as if you are being watched, in the sense of a predator silently trying to hunt you down. But you'll never know, so you just keep on wandering around the monstrosity.