Sorry of this was brought up in another thread, but do we know how out or in flux the 13th is with the other shards and the Source?
Assuming of course that it was the first attempt at a rejoining it seems to have an odder time line than the First has with the source. I can't how long ago on the source the first appearances of voidsent is. I do know that at least 1,200 years ago there was plenty since you can't make an ark that's powered by them if you didn't know they existed.
Yet we also know Elidibus at least wishked away Unhakalhi from it and he only seems to have appeared on the source recently. I don't remember who what's her name said plucked her from the 13th, with the same bait Elidibus used on Ardbert and friends later on, and plopped her onto the 1st. To encourage them so that the 1st could then be ready for a rejoining. At which time she was to kill them all. Only to still be around a hundred years after the flood started.
Then we have a voidsent pop in with Ryne's new bestie who says she's from Elumore even though no one seems to have remembered her?. That being present day on the 1st.
I mean this wonky time line and time sync could just be another thing that's like this because the writers want to use the void, but aren't seemingly sure how exactly they want to. While also trying not to get themselves into a corner with putting in a proper time line.