some words to your description how to flash your custom rom:
First: twrp does not recognize internal storage. Result: long searching for a working twrp
Second: eu rom did not boot
No chance to change anything as the Deskopt PC does not recognize the MI6 internal Storage anymore.
After long searching i installed the miflash tool and installed the gobal fastboot rom.
Now global rom is working. But it took me several hours due to missing complete and correct descriptions.
you should work on your description and the suggested twrp.
Greetings
First: twrp does not recognize internal storage. Result: long searching for a working twrp
Second: eu rom did not boot
No chance to change anything as the Deskopt PC does not recognize the MI6 internal Storage anymore.
After long searching i installed the miflash tool and installed the gobal fastboot rom.
Now global rom is working. But it took me several hours due to missing complete and correct descriptions.
you should work on your description and the suggested twrp.
Greetings