User blog comment:B214/Volume 22 spoilers/@comment-24583889-20160730034934

I might have a theory on who's Bina's true identity is. Just hear me out, while everyone believed that Bina's origin/identity might have something to due to her name "Bina" which has relationship to the Tree of Life, how about we focus on her last name "Lessthan."

If we think this clearly, Lessthan is nothing more the combine words of "Less" and "Than", which by clear definition of well less  -_-. Let's say less can be interpert as anything like in value. If something valuable is less valuble than it should, some might say its "WORTHLESS!"

Just hear me out. Is it possible that Bina, who be stated to be already a pure blood devil before aiding Issei in the Azazel Cup, is actually a devil from the house of Belial.

Think about it. Her head of her household was arrested for treason and her household might end up having the same fate as Astaorth household. In order to redeem her family household, she decide to join the only person who can possible help restore her family's repetuation, which is Issei, who is idol of the underworld.

However there is two problems. Her first problem is submitting herself to a well known pervert and want to test Issei's skill as king before properly giving herself away to save her clan. And her second is her identity as a Belial. Since the Belial are now label as traitors of the Underworld, many nobles and civilians will despise her and it might ruin Ise's reputation just for her being a Belial and even ruin her family's reputation even worse if Issei can't do well as a King in the Azazel Cup.

So that's why she wear a disguise and go by an "alias" (For all we know her name could actually be Bina Lessthan and no in the under world literally know who she is) so she doesn't ruin Issei's reputation for her being a Belial and not ruin her household's reputation even further if things doesn't work out well with Issei.

As who exactly who she is, I might say she could be Diehauser's daughter, who could make it even a more better reason to restore her family, especially her father's, reputation. Or she just someone from the Belial Clan that just want to restore her household that to its fame and glory.

Thank you for reading this and please don't be too harsh. It's not fake, it just my opinion.