Here's a nob, dudes.
After a brick (before I installed OmniRom 4.4.2 and i tried downgrading) I found on this forum how to flash a chinese rom thanks to Huawei Update Extractor (update.app), then I tried to install stock firmware with Huawei Update Multiloader Tool 188.8.131.52, following all processes in order to this guide:
but after reboot, under voice "Download information" appears "Firmware (HandShake Fail)". Here's a screen:
Someone helps me. I'm just going mad.