"I'd like to play my character as described in the thread in your RPG, however.. - I sort of want to be an "anti-party" member."
This is the part I misinterpreted.
"My character is a bad guy. No, he doesn't work for the side of evil."
Maybe I should have realized at that moment what he meant, but...
"If you think about him in D&D terms, he's.. chaotic neutral"
Combined with the rest of the message, I thought that he might have wanted to be part of a different faction. That's all. I probably should have remembered that this was a PRIVATE message. Ah well... Sorry again.