Quote Originally Posted by Anonymoose View Post
The thing that gets me is the timeline boundaries.

The Source (Patch 3.4) = The First (100 Years Ago)

That's when the sin eaters appeared on the First, so no matter how you mess with the relativity in absolute time passage speed between the two dimensions, which does oscillate, it never goes backwards. Even if time stops whatever inspired Amdapor could not have been a direct glimpse of the Flood of Light on the First 1:1 at the time it was happening.
You are assuming Sin Eaters never existed before the events on the First. That is a bad assumption. Sin Eaters are the product of Light. Light exists on all shards. Hell, Light likely existed pre-Hydaelyn and Zodiark. Just because there is no lore about it doesn't mean it never happened.