Turns out, I had forgotten the -strict unofficial flag. Also, I was trying to re-encode a video that was already broken. The real haunting was the error message:
💀💀💀💀 (An unwatchable, desynced, artifact-ridden nightmare that made my CPU fan scream like a dying banshee)
I need to get something off my chest. I think I watched the wrong version of Ghosts last night.