I have said a few times that I think the game could use a focused enemy (or enemy race) to draw more interest by exciting the story.
With the original lore it was the Gek First Spawn in earlier times. The sentinels were (and are) more of a neutral obstacle to civilization as a variant of nature’s wrath.
With the new lore we have an expiration date. However, it seems there may be a mysterious RL person and an underlying code unseen by the Atlas that are projected to affect things to come. I have suggested that this may be a deliberate kill-code or virus introduced to the system
And I am sure that @zsigmond will say we already have Emily as the big bad.
But, it occurred to me that we may have already seen the enemy to come (the tool the virus uses in other words). Given the story of the Gek First Spawn, I see it highly probable that a section of the First Spawn strategically did what they always do when facing a threat. I suspect they hid deep in the simulation when the Korvax “conversion” was occurring and could not be stopped. (Plus this would be an easier way to program a new threat.)