Hossa didn't start that way. I remember the scouting reports when he was drafting stating he wouldn't recognize his own goalie in a line-up. (I miss Hoss!) I have heard Demidov described as "relentless", which is a good characteristic for defensive presence.
The think that I thought was interesting for Demidov is that I heard he's been in the MHL from 15, and even as a 15 YO was putting up a PPG. This is a guy who "thinks" the game at an incredibly high level, and that tends to translate even if some of the moves that he pulls off won't work at the NHL level. I trust the guys with the hockey IQ a lot more than the early developing physical guys who dominate based on getting their man-strength before everyone else (aka - Zach Bogosian).