Okay, it works like this. Lets assume the condesce went into the past to conquer the post-scratch session. This could be enough for a scratch, especially in the absence of ectobiology.
She goes back in time, builds her empire, other things happen. Sufferer and Summoner do the same thing, to try and stop her, but too little too late.
Condesce goes on to take stuff over. Basic time loop logic fills in everything else. Including her younger years - she's not a fish out of water, she's filling a role that she'll ultimately prep for herself. To others, it looks like she had a normal childhood and then SUDDENLY SHE KNOWS THIS WEIRD STUFF. That normal childhood was the result of the time loop trying to assert itself. In fact, the Condesce might probably even be changed by the experiencing, having both sets of memories.
Same for the sufferer. At some point, he heads back in time and hits himself. Pre-scratch mingled with the determined attempts of loop consistancy by post scratch. The post scratch session eventually justifies this somehow, internally, but the impetus, the reason, was the collision of these pre scratch trolls.
And then it happens again with god-tier Tavros ancestor.
Eventually the younger kids arrive, having sent themselves back, and also their ancestors. The ancestors in an attempt by the timeline to stabilize itself internally and independently from the pre-scratch session.