to be fair, there is something pretty interesting called THE COLLAR, that if you break it (4 or 6 corruption depending of which route are you following), it gives you a pretty strong advantage. i mean, if you know how to optimize your resources you can defeat the demons without using the collar, but you have the tool to defeat it without much issue.
??????? Are You Dumb??????????
...Sooooo... you clearly haven't gotten to the point in the game where I am because you'd know you can't use the collar against the Sloth Devil Boss... soo what was that again??? I'm playing on normal mode, which is pretty hard, but from this comment, I can easily tell you haven't gotten to the point where I am. Also, there is something interesting called BRAINCELLS which I suggest you use before trying to seem like a SMARTASS because right now you just seem like a DUMBASS. How about you get to my level first then talk? On top of that, I'm playing on autosave only and only had to use my Collar 5 times in the Run.
You can definitely use the collar on Belphegor but to do that you need to dismantle the barrier, which is done by interacting with all the light orbs around the demonic domain. Chances are, you missed the one that requires stocking 10 bombs at the store, which relocates Aaron to the quarry in the next loop, from where you can Open Domain II on him to get to the last orb.
I mean, who is the Dumbass? the one that searched all the area, and did dismantle the barrier, thus he can use the collar in the bossfight, or the one that in his haste to defeat the boss didn't search all the area?
Obviously, i was thinking that i was speaking with someone that did in fact, played the mountainreach area, but well...