I might be emotionally scarred from the amount of Horrific Visions and accompanying assaults I did in 8.3. They were neat content, and I really enjoyed the challenge of pushing myself to play better on multiple classes, but I also felt completely burned out by the end of the patch.
By completing both the Horrific Vision of Orgrimmar and Horrific Vision of Stormwind solo while all five masks are activated (the hardest version), you earn the Mad World feat of strength, which rewards the title, The Faceless One. I found that it was significantly harder to do this on cloth characters than any others. I really pushed myself to master my mage and warlock, while it felt like the other classes came easier. In the end, I earned Mad World as a discipline priest, demonology warlock, retribution paladin, elemental shaman, and balance druid. Five classes down!
I also managed to save up the 100,000 corrupted mementos from Horrific Visions to purchase the Wicked Swarmer, shown at the top. It’s a really great mount I think. The color looks good, it’s a cool model, and it’s small enough that it isn’t annoying when using it. I decided to save up for it on my warlock so that my priest, my main, could spend the corrupted mementos on sockets.