Poor ending

Rating: 5/10 (31 December 2018)

Wanted to see this as it's so highly rated.
Interesting beginning and the big reveal with the photos was well done, but last ten minutes was a gore fest: one killing after another.
And how did Chris turn into such a brutal, stone cold killer who gets beaten and stabbed but just shakes it off?
Felt as if the writer ran out of ideas so just went for clichÃ©d ending.