Johan(n) Liebert is a canon native of Naoki Urasawa's Monster, currently played on the Sueniverse by Skazka. While kind of memetically known around the internets as the personification of Evil and/or the Antichrist, somehow fleshing out his backstory for a setting that includes Repo! and Watchmen elements just made it much, much worse. For one, this Johan is all Goddamn baby duckling about Adrian Veidt. (Johan is just his primary pseudonym; there's a reason one of his tropes is I Have Many Names. Megan has a theory that Urasawa intended his surname to be Liebhart, just for the irony of naming a beautiful but sociopathic character who seems to be asexual "Sweetheart".) Either way, he's a really quite pretty blond with curious eyes who looks good in a turtleneck. And also in a wig. His ability to Hannibal Lecture people is actually pretty much canon, but he cannot actually kill you with a warm smile and a nod of the head. Promise.
He will send you ominous emails. He will invite androids to tea at your residence without permission. He will write postcards to Hans Landa's civil partner. His pants are full of roses and his heart is full of lies.