Guess what? I've been using the Invisible Spiral this whole time, and it's glitchy. But Titnosis and Assnosis (yes, he actually added it) work just fine anywhere.
The amount of damage that a Girl's Shields can take in the higher levels of Countryside is staggering. The Overflow Errors cause their HP to loop through -21,474,850T (-21.47QT) to 21,474,850T. (21.47QT) This can loop multiple times. I'm currently in the Lv9200 range, and they loop at least eight times per Girl. Thankfully, the Overflow Errors aren't harming gameplay, it's just a visual bug. Of all the things that need improving, this is pretty low priority.