Of course none of that mentions how X's suffering circit comes into play and how it's the "true form" of the virus.
Mind telling me what such a thing as true form even means? It means literally nothing beyond "non-elaborated relation". Also: "might not be canon" RZOCW clearly says.
Really, no source actually says anything direct about how X's suffering circuit (read: worrying) applies to the Virus. Not even RZOCW. All sources outside of RZOCW and RZOCW itself say Repliroid free will/suffer circuit/worrying causes irregulars under certain conditions, and all sources including RZOCW say the Sigma Virus causes irregulars. So obviously the two are innately connected. That is all that is said.
And that Zero is actually infected and still spreading said virus.
RockmanX6. Having a piece of Zero's body make a genius Repliroid go bonkers wasn't obvious enough?
- The Colony Virus. Honestly, why did they even bother to add this in? Wily's helping Sigma; they could easily have attributed the Zero Virus to Wily without needing this virus. For that matter ...
Why shouldn't it have existed? The entire point is that it merges with Sigma Virus to create a new entity. With the one or two mentions it got, they explained it adequately.
- The Zero Virus. It really never needed to be labelled as a "virus" in order for it to work. It isn't bad on it's own, but the game already deals with the Maverick, Sigma, and Colony viruses! What's worse is that this virus didn't really need to exist. They could have done the same thing with the floating Sigma heads.
What's with the bias against the term Virus?
The Sigma Virus merged with another and took on Zero's identity, making it suddenly become much more dangerous and allowing Zero to awaken. Why would something derived from a virus or two suddenly not be a virus?
The entire point of the revelation that is 'origin Zero' relies on the transformation of Sigma to Zero. The entire alternate route to awaken Zero relies on Eurasia's crash. As such, both the Colony Virus and the Zero Virus are entirely necessary elements of RockmanX5.
- The X virus. This was just a bad attempt at a "cool" enemy.
There is no X virus, what are you talking about?
- The Nightmare Virus. Honestly, it didn't need to be called a "virus" and it's just adding fuel to the fire.
The thing invades Repliroids and alters their genes. What else than a Virus would you call it? By making it a Virus, Capcom elaborated a great deal on matters of Virus substantiation and their weaknesses to conventional and program weapons. Furthermore, it's entirely of note that such a thing could be made from Zero's DNA.
Each virus is fine on it's own. However they become a complex mess taken all together. What's worse is that they all sorta do the same thing! So you have several viruses that all take over Reploids, but they all have subtle differences. Except for the Maverick and Sigma viruses, which are interchangable. But that interchangability is a detraction because then you have Capcom talking about Zero infecting Sigma with the Sigma virus.
The differences and purpose of each is pretty blatant if you ask me:
The Irregular Virus: Any Virus that turns Repliroids into irregulars.
The Sigma Virus: The Virus that came from Zero, eventually merged with Sigma, and turns Repliroids into Irregulars. Could turn Zero into an irregular but is not potent enough.
The Colony Virus: The Virus that was spread on board Eurasia with the purpose of merging with the Sigma Virus to create the Zero Virus.
The Zero Virus: The combination of the Sigma and Colony Viruses. Is like Sigma Virus, but resembles Zero instead of Sigma and is far more potent in turning Zero into an irregular.
The Nightmare Virus: Extremely powerful virus with a physical form, attaches onto Repliroids, invades their bodies and alters their DNA.
ALL of this is outright said in the game. No manual nor sourcebook needed.
And the Suffering Circit also didn't need to be added into the virus' already complex backstory. I mean, really. As if Zero's code corrupting Sigma wasn't enough. No, now we need to add in how Cain's copy of X's circuit is partially to blame. So, not only do we need to understand that viruses cause Mavericks, we also need to get behing the suffering circit and understand that this mess came about by their interaction.
Suffering Circuit = Worrying = The ability to think, feel and make your own decisions = free will.
No way that the Sigma Virus which creates irregulars relates to free will, that's just such a ludicrously overcomplicated concept!
And you can add "the origional Zero virus" to the list of "viruses that don't need to exist".
Without the original virus, Sigma being a virus is unexplained and we'd have a PLOTHOLE.
Because even if I'm wrong and it isn't confusing at all
It is NOT confusing, discard everything you know, go play the games in order and pay attention. THIS is the flow of the X-series:
X1: X worries and because he worries, he has true free will. Repliroids are modified versions of X. Repliroids can go irregular because of free will and glitches in their brain...
X2: Sigma is spreading a virus to forcedly create irregulars. Mysterious wireframe bosses attack you. Oh and Zero was the last of the Wi.. Numbers.
X3: ZOMG Sigma is the virus and it's a wireframe! So that's what that was! So that's why Sigma revives! Huh, Zero has to fight with X someday?
X4: Hmm... Zero was an irregular, who's that doctor? Wily? Wait, why'd Zero turn good? Why'd Sigma turn evil? X and Zero fear they might turn into irregulars...
X5: The world is thrown into mass chaos thanks the Sigma Virus. Hmm.. Zero is getting stronger from it. Does he have antibodies or is he a danger? What?! The Virus from Eurasia merged with the Sigma Virus and now resembles Zero?! Huh, his data is the same, the virus is everywhere but there's no virus reading. That is Zero's true self.. They're accusing each other of being irregular, epic battle between X and Zero! Ah, the virus purifies his body.. So the Virus comes from Zero?! Oh! So that explains the flashback from X4! Oh wow, Wily started all this mess by putting a virus inside of Zero!
X6: Hey, the Virus is spreading from that piece of Zero. And a genius scientist can make a Virus by using Zero's DNA. Yeah, that makes sense as the Virus originally came from Zero. Oh, this Virus is very strong, so it has a physical form. I guess that explains why Sigma Virus can sometimes be a wireframe or a floating sigma head, it's becoming physical!
What you're having trouble with is reading too much into a vaguely worded non-canon piece of text that was never even shown within the same series!