Just ignore the sphincter. Yes, he is annoying, but no more so than a buzzing gnat. Eventually he/she will tire of being so childish.
Hyperventilating over this current troll's antics will only encourage him/her. I received several rude, crude and lewd messages in the past. I glanced at them, laughed at the person's foolishness, and deleted them without a reply.
The admin seldom interacts with the site. Report them and he will be taken care of by admin. I got spam from him too, but it always makes me feel tingly when trolls attack.