Actually, I revise what I previously said about where Robert would be after the Fall of Beacon. He would probably think he was responsible for the whole thing and go into hiding so that no one would find and possibly be hurt by him. Maybe when he's all alone, isolated in whatever the deepest hole he could find, he'd realize that his semblance was the cause for his terrible luck and that it can be controlled. Then it would be a question of whether he'd immediately go looking for everyone since he now knows how to keep them safe from himself or whether he'd continue to be alone as some sort of penance for what he'd done.