i thought that too because the demons react so weird onece they hear ashiyas name and the legislativ even asked about his father ? he said there are not many HUMANS left whit that name so what about yokai or maybe exorcist but the yokai makes more sens for me. the exorcist should be known but you would not tell that your family is related to the yokais :D
Imagine this, the former master of the mononokean was Ashiya's father. Duhn duhn duuuhn~ What do you guys think? Plausible?
But since it was revealed that the former master of the mononokean was a youkai, doesn´t it make Ashiya half human half youkai? ^^''
Two possibles reasons why Abeno fainted: He opened the door twice and didnt tell to Ashiya; Abeno is getting weak or sick because of mononokean.
Tbh is a surprise that a human is able to be the master, open the doors looks to demand to much energy.
If we think about Ashiya is the protagonist, maybe he is the one that have to be the master, I think (theory) that he is half-yokai nothing about his dad was mentioned yet. Of course Abeno is the biggest mystery he hides so many things I think Ashiya will save him in the future