Through TWRP, I have performed a Factory Reset, which was unsuccessful. I then went through Format Data to remove the encryption:
Format Data will wipe all of your apps, backups, pictures, videos, media, and removes encryption on internal storage. This cannot be undone. Press back to cancel. Type yes to continue.
As long as I can get to a state where I can flash new roms and boot without the encryption prompt, I don't mind having to root again, losing internal data (which should've happened above), or having to reconfigure everything (that's half the fun).
adb and TWRP are still functional. I'm downloading the stock recovery and factory images to give them a try as well, though the download is crawling and it will be some time before I can test it.
Has anyone else successfully solved this?
Edit: Solved.Flashed all factory images, performed a factory reset, re-rooted, set up TWRP again, and got back to a current rom. For anyone else who runs into this in the future, I had to use the stock recovery, not CWM or TWRP, to successfully wipe my device.