Hey guys I'm just looking for anyone's thoughts on the basis for a story below:

Names are something i was gonna add in later but so far,

The story starts of following the life of seemingly average early 20's male protagonist whom after a few pages we realise that he is always seeing the faces of random people around people around distort and look like horrifying creatures, he thinks to himself "oh not this again" and runs for his sanctuary which is just where he lives which is above a bakery owned by the woman he is in love with but has never really exchanged too many words with. After a very brief/awkward encounter with her he makes it to his room where he thinks to himself "dam filthy demons" and the reader sees that all the walls are covered in strange symbols apparently used to protect against demons which the protagonist has spent most of his life researching thinking demons were always out to get him.

While sleeping there is a sudden burst of flames and a demon appears to him but soon realises that he trapped in one of them symbols, the protagonist then douses him with holy water. The demon is rolling around on the ground writhing in agony screaming "why are doing this to me?" in a very comedic way. After awhile the protagonist eventually lets up and wants to hear what the demon has to say, the demon explains that the protagonist is in actual fact a demon well half-demon (which is why the symbols or holy water never worked on him) as he is the illegitimate son of Satan.

He explains that Satan is dying and the underworld needs a successor but the only candidates are the children of Satan when the protagonist finds out he has seven brothers and that they are all exceptionally wicked and heartless "even among demons", the demon explains that the underworld would be a sucky place to be if any of them took over so he wants the protagonist to do so. To convince the protagonist the demon tells him that with the power that he attains he will be able to have the woman below fall in love with him, of course that's all he needed to hear and signed straight up.

The demons explains that the protagonist is too weak the way he is now but he knows of an ultimate power hidden somewhere in the underworld, thus they head out to get it. When they find it it turns out to be a soul which has been embodied into a skull that floats though he also incredibly perverted (always flipping up girls skirts and so forth though he can not be seen by humans). The skulls explains that he will be able to absorb the power of his defeated brothers thus being able to defeat them one by one starting with the weakest, the skull also follows the protagonist thinking he'll be able to see girls.

Upon their return to the real world they are attacked by an arch angel (they don't anyone to succeed Satan) whom are all females through their combined might and a few comedic scenes they defeat her but she eventually fall in love with the protagonist and follows him later after being defeated a few more times.

The demon takes him to the first brother in the real world where they get into an epic fight that has to be finished in the underworld and the protagonist defeats him absorbs his power, thus gaining more confidence and is finally able to hold down a conversation with the woman he loves.

This is all have so far but would love to hear what other manga fans think of it.