And again if you are unsure about parts there is absolutely nothing wrong with saying "I'm not sure about this part" or "who is this person again", I am happy to answer. It is probably a better experience if you know what is going on rather than suffering in silent confusion
My understanding is that the version of Arachne we are familiar with is essentially the reincarnation / child of the Arachne that is serving as the POV in this memory interlude. It seems as if the original Arachne was somehow twisted into some kind of horrific monster bent on destroying the collapsing remnants of the Empire. She (or a fragment of her) sought to take over a Weaver/Builder that had the mutilated form of an imprisoned Ishtar as a foundation. Something unknown happened (with the Celestial Nail involved) and the resulting entity that formed after a reboot is the Arachne that has been serving as the protagonist.
Yup, more or less correct. Here are the current puzzle pieces:
Original Arachne (Alpha Backup/Arachne Weaver)
1. There was a vote option relating to Fringana, which was Axiom Corporation's major research facility and very fun place. This appears to be the origin of Arachne. Axiom appeared to want to experiment with creating god-beings, and Arachne was a failed prototype they stuck in a Weaver/builder.
2. The current set of updates. Arachne leaving Fringana and living With Ishtar, then leaving and living inside the Margrave's Palace.
3. The very first update's opening lines, which take place before the Collapse.
4. A vote option relating to the Nail, and the Collapse.
5. At some point, this Arachne killed Ishtar's mutilated form in a Weaver/Builder. She also received the title, Deathweaver.
6. At some point in the indeterminate past, something happened, and the original Arachne ceased to exist as a conscious being.
Current Arachne (Omega Backup)
1. Current Arachne activates not having any memories whatsoever, inside a chassis that appears to belong to Ishtar. She is immediately attacked by and ejects a Dragon Talon, which is a form of infohazardous entity unique to the Dragon, effectively the most powerful living being in the setting and the attack dog of the Emperor (to simplify things massively).
2. She finds Ishtar's remaining fragment inside her.
3. She creates numerous subminds and finds lot of fun games that appear to have been there already. She finds the Celestial Nail, which is some kind of birthmark she can't get rid of and it's very ominous.
4. She resurrects Ishtar, who tells her that she was killed by Arachne, or at least a past version of her. Ishtar explains that the talon was something she took into her willingly because the Dragon was asking for volunteers.
5. Arachne trusts a guy named Don Hidalgo. This turns out to be a bad idea.
6. Arachne finds out that the inside of her mind is weird and freaky and that she needs to get to the bottom of it, because her mind is functioning like an iceberg where large portions of her existence are unknown to her.
7. She trusts Don Hidalgo again. This is less of a bad idea, but doesn't really work out the way they hoped.
8. So she trusts him one more time and this time it works out a little bit better, but now everyone's in Gundam.
The Last Joust (Both Arachnes alive simultaneously)
9. Except that Arachne Weaver is not Current Arachne, who exists at first in the Last Joust only as a voice in Arachne Weaver's head. Ix-Chel and Diana are there. They were fragment voting options from the very beginning of the quest and now exist, somehow. Also, they are lovers of Arachne Weaver. This is meant to be confusing because as it turns out executables are very powerful! Powerful enough even to reorganize a shattered mind into a new shape no one recognizes.
11. This is a problem, because Current Arachne reacts to another version of her in a typically Imperial fashion, by plotting by Highlander rules how she is going to kill the alpha backup and regain a body.
10. The Celestial Nail explains some of this to both Arachnes, revealing that they're two separate backups. She then separates them apart so Omega Arachne, space gremlin that she is, doesn't kill her past self because she's territorial. She also explains to them her own origin: She, and the other void cylinders (the weird pinging hexagons that chased around Arachne's Drones) were another god-being attempt by the Axiom. So was the Concierge, one of the polities players have met. There are two others the players have not met that she mentions as well.
11. This allows Omega Arachne to take over joint-administrator control over the simulation she was granted by Don Hidalgo, who has absolutely no idea this is going on because he is busy doing pirate hijinks and playing a gacha game with historical heroes. Arachne Weaver continues on blissfully unaware she is effectively a dead woman walking and that her wives are dead too. Omega Arachne is now watching this like it's the Truman show and she gets to decide who lives or dies.
11. The simulation continues to fuck with Arachne Weaver, the alpha backup, now accidentally cracking open an actual historical memory of hers while she's sleeping. Arachne Weaver is experiencing the entire memory as a dream, which is very confusing to her as she thinks she is a gundam pilot, while the current Arachne is watching all of this from the outside in and is also confused and also fascinated by what appears to be an authentic memory of the Empire.
12. Yes, that means that the current Arachne knows that Weaver was effectively raised by Ishtar, and then betrayed Ishtar.