I like the theory that Clara could possibly be a Deity.
From what we currently know, Clara's father is an "adventurer". It's a perfect disguise for a Deity to be able to send unusual gifts to their family that nobody else in the Netherworld knows about, possibly because the Deities made it and is also the perfect explanation as to why he isn't anywhere to be seen despite an entire year going by. (So far, he has yet to visit or appear besides a mention once or twice.)
I also like the theory of Clara's mother being an Ex-Evidol. It would be a good, lighthearted backstory as to how their family came to be. A Deity falling in love with an Evidol, starting a family of happy sing-song people who are naturally upbeat. It's a very fun and interesting story to me personally.
Besides that, my logical reasoning as to why their place of residence, the "Gaya-Gaya" forest has unnatural and unique flora & fauna compared to the rest of the Netherworld, is that the entire forest is a work of their father.
Why? (Spoiler for very recent chapters)
>!We know from recent chapters that the hill with a field of flowers Merize and Henri used to frequent, the "World Between" has a flower that is very rare in the Netherworld, said to only be cultivated by the Deities.!< What if her father was one of the Deities that are tasked in the cultivation of flora & fauna, and that the "Gaya-Gaya" forest was one of his many projects. It could be a nice connection that could give reason to their unique way of living. It could also be a good tie to the origins of their bloodline magic. An ability of creation, something that their father who is possibly a high Deity takes great interest in. Seeing as how he likes finding new things, possibly creating new things as well.
Another reason why I want this theory to be true, is that it would personally be very interesting. Our Iru-army trio always loves to be together, so Clara being left out in the Deviculum is a very painful thing she has to endure everytime. First it was Iruma going at it alone, then Azzy got in next. So isn't Clara being added next in the Deviculum would just be swell?
How could this happen?
Well... We know that Clara isn't very keen on showing her wings. One theory suggests that this could reveal her Deity origins. Many other theories exist, but this genuinely sound the most interesting. Clara hides a lot about herself even compared to the other two, so her being the first to reveal her secret in the trio would be pretty cool.
It also gives her an IN. A reason to be present in the next Deviculum in many ways. Could be because Iruma and Azz tell her that they have to go to a Deviculum again, leaving her alone once more.
What if, her mother takes note of her lonesome, gives her a talk about it with her father, and provides her a chance to attend with them. It feels very in line to a surprise she would pull on the two.
We also know that Baal currently has ties with Shura, a Deity princess. Iruma has nothing that could even remotely rival it. (Unless Thoht is revealed to be a high Deity that could rival even Shura) To balance the scales, a twist where it's revealed that Clara and Shura were once childhood friends, specially with how close their energies are and with how possessive the two are, it could give Baal a thorn in his side while also providing a bridge to Iruma and Shura, having Clara as a mediator via a "catch up conversation" with the Deity princess.
(It would also be interesting to show a noble/elegant side of Clara that would only happen if she were to keep appearances up as a Deity, possibly part of a deal with her parents with how she needs to act properly if she were to attend)
Having the three of them be able to attend the next Deviculum and having Clara suddenly appear as a Deity in front of them would both be a shock and a big middle finger to Baal. Sounds like a fun time to me, and honestly I hope even a small part of this theory is even right.
Thank you for coming to my Ted Talk, I wanted to know your guys' thoughts on how plausible this could be, and if you found any inconsistencies in the information I provided, please point them out. See you in the comments!