I haven't played demon souls - but in dark souls in regards to bosses they teach you the main killing technique right on the first boss! Most of the harder bosses I've run into die to this same technique - even the capra demon that lots of people talk about, I died to about four times before getting him with it.
There was this butterfly that took about 15 goes, I'd estimate. Not sure what the trick was supposed to be with that one, so I just upgraded the heck out of my crossbow.
Anyway, it is rarely said and it is a shame that is so, but just having taken on the risk of the game at all is honourable and noteworthy. To not even face the risk is the real suck!