I have some vague memories about it. I think it took place in some sort of futuristic post-apocalyptic London. The main character always wore a mask and was a runway, constantly chased by “the authorities”. There were constant switches between this futuristic world and the present one (which was just our normal current world), but both worlds were somehow connected. In the end, the main character turns out to be just insane, so this whole futuristic world where he was a runway and some sort of a hero was just made up and didn’t really exist. In the final scene, police find him with a sniper’s rifle next to a window, aiming at someone and looking like an extremely disturbed and schizophrenic person.
Franklyn (2009)