[Help] Failed to mount '/data' (Invalid Argument)

[metoobe]

Huawei VNS-L31C432 (3GB) (P9 Lite)

so i was trying to rollback from Elite Rom to Stock but every try to unbrick makes the phone get stuck at Huawei Blinking Logo or "Your device is booting now"...
Going for twrp everytime i try to install a rom or something says Failed to mount '/data' (Invalid Argument) + same thing for cust and system i guess.
Those last 2 i've fixed changed partition to something else and change to ext4 again but /data doesnt allow me.
Cant also Format Data, Repair File System and always says 0mb size :/

Apparently the issue is because the partition was encrypted in Elite Rom and now the phone doesn't boot into Android.
Fastboot works
Twrp from MM works (3.0.2) (used the rollback package and from the charging animation looks like i'm in Marshmallow), the others from Nougat don't.
Dload method with C432B160 works but i get Black screen after updating it.

Any help? how can i use DC-Unlocker to help me unbrick the phone?

[Valdemaras]

You may try method 2 from this repair guide here https://www.dc-unlocker.com/DC-Phoen...epair-tutorial make sure you read info on top though as well.