My work step..
My work step..
Upgrade via PCsuit then use Flashtool create 14.2.A.1.136.tft (cant not unlock via Fastboot)
Downgrade to .290 (cant not unlock via Fastboot), But I use Flashtool64 Unlock my C6902 by downgrade to .290 (I'm not sure if unlock via flashtool on .136)
then flash 14.2.A.1.136.tft that I has created, then use fastboot flash DoomKernel v6, restart into phone, open SuperSU upgrade and install.
Turn-off and flash 14.2.A.1.136 Kernel (Only kernel).
:laugh::laugh::laugh:Finally I got Officail firmware with rooted. :laugh::laugh::laugh: