My guess is it has something to do with the bootloader, but I'm not too familiar with the way Android devices bootup and whatnot. This is on a D801 (T-Mobile version), and I was running a stock rooted rom with TWRP recovery installed. I'm posting here instead of the T-Mobile subforum because I don't think it's an issue unique to my model.
Since I can load up TWRP just fine, I don't think it should be too catastrophic of an issue.
Any help would be greatly appreciated