Armin Meiwes, who does indeed speak English, seems remarkably normal in interviews. (The thing about absorbing his victim's abilities is the weirdest thing he's said, and he only mentioned it once as far as I know. But even that is no weirder than Catholicism.) He's just a normal person who butchered and ate another man. When he talks about it, it all seems perfectly explicable -- not that I'm going to go out and do it myself. For one thing, I don't live in a thirty-six-room farmhouse in the German countryside, I live in a three-room apartment in Manhattan, and my neighbors would probably realize that something was amiss. I also don't have a great big chest freezer like Armin. Also, more importantly, I'm not as desperately lonely as he was. I yet hold out some hope of keeping a man through some other means than eating his flesh. "Since zen," as Armin says, "he iss alwayce wis me."
If you want to be Armin Meiwes for Halloween, incidentally, it's very easy: just grin a lot and do a heavy German accent. The guy in that one episode of The IT Crowd (who, being German, doesn't have to fake the accent) pulled it off very well. "Maurice Moss! Mmm, he soundss delicious!"