My friend have softbricked his phone.

I have unlocked his bootloader ,installed twrp(2.7.1.0).
He had cm 11 and cm12 ,then he camed back to stock[ KOT49I.A14187 ]
After about a year since bootloader and twrp install ,he updated stock[4.4.4 to L] ,it went to twrp and it's still in twrp.
Now the phone is in bootloop[recovery all the time] ,restore works but phone is still in bootloop.