Is Zero the original carrier of the Sigma Virus?
Yes. Multiple Japanese resources, as well as the dialogue from MMX8 prove this to be fact. Though this has apparently been known for quite some time in Japan, we as American gamers weren’t given real hints at this until the events of MMX4. Zero’s infected form is called his “true self” by Sigma, who knows that Wily originally built Zero. He talks about dying for the good of humanity. He talks about “finally” defeating the virus, though later installments in the series proved to be false. If the events of MMX8 are completely correct, and Sigma has been completely destroyed, then it would appear that the virus went with him.
