I can confirm, that I always unlocked the bootloader before flash of something. I was able to restore my phone several times with fastboot flash method to fully functional condition (but without multi-language after it )
Brick came with flash of orange state zip with TWRP flash method.
More details you can see on screenshot. Orange state zip file changed phone name from "x650 oversea" to "s2_plus".
It was half bricked after reboot. Fastboot was still available, but did not match with fastboot restore expected device name.
Therefore i could not recover my phone as before.
Final brick (dead as stone) occoured after my try to solve the half bricked status by usage of TWRP in fastboot boot mode.