Proxies are a Successful Fusion of a Person and a Karma Core.
We start off from Remielle's Quote,
Here, it is pretty clear they are talking about Helios Academy here, also what they gained from that place.
Remielle started working with Helios Academy (Professor Arche) and Sunbringer on Project Sunseeker, the project where they tried to fuse the user of a VH weapon with the Karma Core inside it, so that they could utilize more of the power. This resulted in Vike completely transform into an enchainer, and Remielle to take a slanted path to the transformation.
Proxies on the other hand, were raised by Carole Arna, and they became the top of their class, and were deemed qualified for the ocular implants.
On a side note, it's interesting how all of the children who got the ocular implants were adopted. Wise and Belle were taken in by Carole, and Truvia and Serpico were adopted by Mosseint of High Ambition Corps. We know nothing about the parents or family of proxies except a crackpot theory that suggests they are Joyous' descendants. It's because some people also say that Belle's eyebrows are Grey, which means she dyes her hair. But she has to be dyeing it from way back in the flashbacks if so. Still, the most unrealistic part of this theory is Joyous actually getting laid.
Anyway, the proxies have ocular implants, they not only have a unique ability to communicate across hollows and mainland, but a specific entity tied to them like Tailless or Qingming sword, which entity is also the source of the combat power, just like Tailless or Qingming sword. It's also said that the reason proxies started having problems with the implants was because the balance of powers has been thrown off, which is suspiciously similar to what leads the Qingming sword users to go boom.
Here's another thing though: The eye colours. From Harumasa's character Demo we see how he was an experimentation of trying to get ethereal characteristics into Humans, probably trying to make hollow navigation safe for humans. On the demo, in the clip where he's transforming back and forth into an ethereal and human, his golden eyes have the turquoise blue color on the right eye. Sunbringer's Power is genesis Reconstruction, which means it has to do with the genetics of humans and ethereals like her. We know that the eye colour is tied to her power is because the creator gave a sliver of Sunbringer's power to Sarah, and her eyes turned into the same Sunbringer eyes. That's what's interesting about the Proxies: their eyes have both the teal and Golden yellow colour in them (see the picture for reference).
Now you might say, "Well, what about Truvia and Serpico? they dont have that" Well, first off, we come to Serpico. His eyes are green. You know how you get green? By mixing Yellow and Blue. You can get different shades of green by mixing different shades of blue and yellow. Truvia on the other hand, has very yellow/orange-ish eyes, kind of how Harumasa retained his yellow eyes after his experiments. Truvia and Serpico also represent the two extremities of the story of Icarus. Serpico retelling flying too close to the sun, Truvia flying too close to the ocean. I will talk about it in a future post in detail.
As we know, MOST of the Void Hunter Weapons are crafted by Flint workshop. This includes Thaumiel and Tailless by Omond Flint(since he was the Flint of their time), including the Omond Research Station for Operation Bagel (Enigma of the Labyrinth)
Omond Flint, Sunbringer and Joyous at the Omond Research Station
This begs multiple questions:Do each VH weapon need a separate Karma Core? If so, then how did they get 3 karma cores without the Hive Lord Hollow? Then again, how did the Qingming sword come into being? If it was made during the OGbringer's time, then we would see a person wielding it. Then again, Sunbringer might be involved with it as seen she is involved with some stuff in the Lemnian hollow, including Banyue. Carole Arna went to the Lemnian Hollow to research the Qingming sword among other things, also calling it "the least sacrifice for the greatest outcome" probably talking about the implant recipients. How did Helios academy get hold of 4 different Karma Core, or did They manage to create artificial Karma cores by observing characteristics from Thaumiel and other Karma cores of the past? This is why proxy was able to resonate with not only Remielle, but also Sunbringer: because their Karma Cores were made on the basis of existing Karma Cores.
Also, the thing with Sunbringers is that they themselves hold the Karma core, which is why they can use any Porcelloy weapon and it qualifies as a VH weapon. This is why Lindverne sketches and tries out many Porcelloy weapons from Flint workshop, gathering debt. Because unlike other Void Hunters, Sunbringers give the weapon the power of Karma cores, not the other way around. This also explains why Proxy was able to use Midbringer's Claymore at the end of 3.2. Because he himself has the Karma core within his implants. Pyrois is the "entity" locked in the Karma core, and communication in and out of hollow is the unique power. According to Pyrois, "This power goes far beyond that" When creating and closing singularity leakages. Truvia also created a singularity leakage to drag in Roxy with her Etheric other in this case. The implants also started acting out since coming in contact with the creator, as its artificial, it started glitching, or perhaps unlocked even more of the sealed power.
What if, the sacrifice Carole Arna talked about in the Lemnian hollow actually sacrifices to the Creator to cultivate immature Karma cores? Then this explains why Pyrois went berserk coming in contact with Thaumiel, a void Hunter Weapon that Arche and others based off their ocular implants. It is basically confirmed that Carole Arna worked with the exaltists. While the exaltists, specifically Landon was studying how to create Sacrifices, specifically Enchainer Larvae, Carole Arna was researching about how to create Karma cores? Or perhaps they already knew how to make karma cores, and were bottlenecked by Enchainer Larvae?
This is also why the title "The Legacy of Helios Academy" holds so much weight. Professor Arche spent over a Century studying how to assimilate a Karma Core into a human Being, and the 4 students (Well, 3 now, really) who have the implants are the pinnacle of this research. This also probably explains why Serpico was made into an intelligent Construct to keep him around. This is because the Karma core and the Power within the Implants was too good to be left to waste.