The very first one has a crazed intensity that a lot of the later ones with wacky vibrato and super high notes and other "look what I can do" stuff just don't match.
I am not sure myself, but research shows that while it's not a unique expression, it barely gets used... It could be a torture device, at least a chair that you can't get out of. Interestingly, one Japanese artist seems to have used that expression in a song many years ago: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-GT-J35TfTuw.html
These arent even all of his most impressive feats. His screaming at the end of Dozing green and whatever the fuck he did (get possessed by a demon??) for the bridge of Magasayou deserves a mention. Thats not a knock on you ofc, its very difficult to keep up with just how much insane shit this guy can do with his voice 😂