Upgrading to El Capitan (and me) broke Windows

Alright, so I tried to be smart and fix this myself and proooobably definitely made it worse. I have a 2012 rMBP. I had Yosemite installed along side of Windows 10. I use Windows 10 a lot more than OSX so I wanted to resize it to be a bit bigger.

I heard installing El Capitan can mess with Bootcamp so I decided to do that first. Lo and behold, I lost the ability to boot into Windows. I got the evil "No bootable device -- insert boot disk and press any key."

I tried fixing it on my own. I decided that if I was going to be messing with boot records anyway, I might as well as resize and move my Windows partition to give it more space. I used a GParted live USB to do that and then gdisk to try and recreate the hybrid MBR.

After that I had an option to boot into Windows. That's good. Trying to boot it would instantly BSOD with a 0x225 error about winload.exe. A BSOD was good, it was loading something from the partition. I created a Windows 10 install USB from my desktop with the intentions of startup recovery. Interestingly enough, it would freeze whenever it got to the Windows logo when it should be loading. I'm not sure if it was an issue with the flash drive, ISO, or what. I ended up creating a recovery USB which copied the system files from my desktop I believe. With that, I was able to get into Windows Recovery Environment.

From there, automatic startup repair was useless like always. I tried bootrec.exe /fixmbr. It said it was successful, but it didn't help anything. With the hybrid MBR though, I'm not actually sure whether it's booting through EFI or MBR. I also tried some bootrec.exe commands, but those gave me "The requested system device cannot be found." /ScanOs would find the install, but /FixBoot gave me that error.

The state my laptop's currently at: when I hold option to select a boot disk I have two "Macintosh HD" options that both bring me to the same install of OSX. OSX boots up fine. The recovery environment did mount my C: drive with all of my files so I know my data's still intact if I can just fix this booting stuff.

Here's some diagnostic output after I finished ******* everything up worse: https://gist.github.com/NullEntity/5461785af697d4902677