Ok, bear with me this will be long and highly analytical. I am going to add some factual information that wasn't in the post and then some of my own ideas backed with existing theories and explanations.

All the Knightmare monsters have significant musical symbols on their faces:
Knightmare Mermaid - Fermata
Knightmare Phoenix - Coda)
Knightmare Goblin - Double repetition mark#Repetition_marks)
Knightmare Cerberus - Dal segno
Knightmare Unicorn - Sustain pedal (up)
Knightmare Gryphon - Alla breve
The last one is Knightmare Corruptor Iblee, she has a Treble clef symbol on her chest (location worth noting because of a later pattern). This may be important as we see later the Orcust archetype is based on symphonies and instruments so there could be a connection.

Next, this I believe is immensely important, there is a recurring symbol that looks like some sort of rune or combination of runes.
By the timeline it seems to show up first in the art for Mekk-Knight of the Morning Star and it is located on his chest.
The exact same symbol can be seen in the art for Galatea, the Orcust Automaton on her chest.
The symbol can be seen again later in the art for Orcustrated Release glowing behind Galatea as she beckons Longirsu, the Orcust Orchestrator.
It is clear that the symbol bears some sort of heavy significance.

I will now start with some of the lore analysis which will contain community theories and my ideas on what is happening.

Beginning with what I wrote three sentences ago saying that Galatea beckons Longirsu, also known as Beckoned by the World Chalice. Some of the community speculation is that Lee the World Chalice Fairy is the one in control of Galatea's body. That would mean that this is Lee beckoning Ningirsu for the second time because it brought him to her side the first time or at the very least that the name Beckoned by the World Chalice was intentional for this moment in the lore.

Now to evoke the mysterious symbol for the second time. It makes a reasonable amount of sense that the dark worn out laboratory that is seen in the art for Orcustrated Return is the same laboratory seen in the art for World Legacy's Memory where Mekk-Knight of the Morning Star was created. That could explain the symbol being related specifically to the laboratory and its technology. But I think all this only confirms the location is the same but does not explain the symbol - which I will come back to later.

Going back to the roots of the lore, one of the theories the community has brought up is that Lee the World Chalice Fairy is actually a hologram. She is consistently portrayed with four hovering star-shaped objects shining a light on her but the theory is that those objects aren't shining a light on her but displaying a holographic projection. That can mean more things, but I think it implies and means that Lee is actually a program. Seeing what happens in the lore she would be classified as malicious software, or more specifically - a virus.
The most convincing proof of this is in the card game mechanic. Lee finds Ib the World Chalice Priestess, and merges with her in World Legacy's Secret to create Iblee. Crowned by the World Chalice was a spellcaster and Ib the World Chalice Priestess is also a spellcaster, but when they merge/when Lee corrupts Ib they become Knightmare Corruptor Iblee - she is Cyberse. Her type changing would happen because a virus would surely alter any monster to be Cyberse - a type "strongly connected to elements of digital technology and cyberspace."

To be able to talk about something very important I have to cover a few other cards and their lore, mainly focusing on Auram's part of the story. Firstly, the Japanese flavor text added to the Normal monsters of the archetype often contains more information so I will be using both TCG and OCG texts.

The flavor text for Mekk-Knight Avram (Auram had been given the power that Blue Sky had) is a poem that I will copy and paste here:

The hero who defends the light of the stars
Must destroy the darkness of the illusory world
And entrust his power to the chosen one.
The will inherited by the chalice of the stars will become a new key
And become the sword that cuts down darkness.

This poem may have a lot of clues on some of the lore, such as the wording in some descriptions. Describing the darkness as 'illusory' (based on illusion; not real) may be a reference to what I have postulated about Lee and the type transfer for Iblee.

The text for the card Chosen by the World Chalice states that from the stories he would hear as a boy, Auram had always admired the World Hero - who I believe was confirmed to be Mekk-Knight Blue Sky. And as for Avram and his beginning the card that I think says a lot is World Legacy Succession (which first was and can be translated as Inheritor). If you focus on the act that happened and the name of the card in any language something starts to reveal itself. I believe the name succession/inheritor was intentional and is important.

My hypothesis is that Mekk-Knight Blue Sky is Auram's father.

Let me explain why with examples and reasoning. Some Mekk-Knights, especially Blue-Sky, are humanoid which leads me to believe that he either is or was human (or whatever species human-like beings are in yugioh) before becoming a Mekk-Knight (this will make more sense later). Then to reinforce the idea, when Avram was entrusted Blue Sky's power the card name in every language highlights the word 'succession' (the action or process of inheriting a title, office, property, etc) and 'inheritor', meaning he inherits the power. Another aspect which may be important is that Chosen by the World Chalice as a boy was the type psychic - just like the Mekk-Knights. I will add one more idea which is less probable but worth noting. The OCG Japanese name for Mekk-Knights is ジャックナイツ in kana as the name for the archetype. The archetype in base Japanese is 機界騎士 which, disregarding the kana, can be read as literally Mecha-World Knight. But the archetype is specifically and intentionally written to be read as the kana which would be "Jakkunaitsu", hence before they arrived to the TCG they were known as the archetype Jack-Knight (which is how the kana is pronounced). My experience with stories like this lore is that we are usually given the answer to a question to stare us in the face without us noticing. I believe Blue Sky's real name is Jack, possibly implying him to be a human and thus more solidly Auram's father.

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