Dean looked into Gordon's eyes and saw the truth.
This could happen to him. This monster, masquerading as a human, pretending to be a good guy, one of the good guys. Killing things. Saving people. Licking his lips as he drove a knife into a bound woman, dark eyes empty and cold.
This is what he could become, walking high on the wire, no net, the only thing holding him there was family. Someone to protect. Someone who looked at him and saw a man. Not a monster.
He didn't need many people. Just a few. To trust. To love.