This episode is a masterpiece. The flashback is everything we've been waiting for the cold, logical Golem who didn't care, slowly being worn down by a relentless, loving child. His reason for protecting her isn't duty or obligation. It's simply wanting to see her smile again .The naming scene is perfect. She named him Dad before he named her anything. And when he finally did, it was after a cat . It's so simple and so beautiful.