Is there nothing more lazy than re-skinning a boss from Dark Souls 1 and making him a boss in Dark Souls 2? Nope. When I got to him I couldn't help but scoff at how lazy that was unless there is some reasoning that is lost on me. He's the same guy except a different color. I think he has the same moves too except for one new attack. Oh, and he's much easier because in Dark Souls you fight him and another guy. Here he is just by himself.
So far the game has been frustratingly hard for me. In a not so fair way, imo. Overwhelming me with enemies so they can chop my stamina down and thus I can't really do much to prevent it. However, the bosses have been very easy with the exception of the bosses that overwhelm you in the same way by there being multiple ones at a time. Neither option being fun unfortunately... too easy 1 on 1 fights or these lame 3 on 1 fights that I only die because I need to put points into stamina.
thought the lore reason was that gwyndolin made illusions of all of gwyn's sentinels in anor londo, and the real orstein ended up in Drangleic and thus we fight the real deal in dark souls 2, he's just old now.
As for the topic at hand, I too noticed that a lot of bosses have mobs at their side, for some it can definitely prove annoying like that giant dog thing (which I still haven't beaten in my main playthrough yet) and the gargoyles kinda suck, too.
Are you talking about the giant rat? I had trouble with him at first too. The trick is to take out the small rats right away, you can then easily roll under him to his back legs when he attacks and not get hit.
I beat the two Dragon Riders and have opened the shortcut to the bonfire but can't figure out where to go from here. There is a door that is locked next to a lever that I cannot pull. There is also the area with the 3 archers near where you open the shortcut but that seems to be a dead end.