Default [Q] Soft Bricked S4 Checked all other threads

Hey guys this is my first post here and I am in need of some help. I have rooted several phones in the past with no trouble before my galaxy s4. I was trying to downgrade my s4 so I could root but managed to soft brick my phone in the process. Trying to turn on my phone I encounter and error saying "Firmware upgrade encountered an issue. Please select recovery mode in Kies & try again". I have tried various methods I have found on the forums. Trying to recover firmware in Kies I get an error saying "Firmware Update encountered an unexpected error". Whenever I try to flash anything in odin I get an error.
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<ID:0/004> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> I337UCUAMDB_I337ATTAMDB_I337UCUAMDB_HOME.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/004> Odin v.3 engine (ID:4)..
<ID:0/004> File analysis..
<ID:0/004> SetupConnection..
<ID:0/004> Initialzation..
<ID:0/004> Get PIT for mapping..
<ID:0/004> Firmware update start..
<ID:0/004> SingleDownload.
<ID:0/004> aboot.mbn
<ID:0/004> NAND Write Start!! 
<ID:0/004> FAIL! (Auth)
<ID:0/004> 
<ID:0/004> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)
I don't really know what else I can try. My goal is to try to get back to stock.