How OLD is Kal‘tsit & Where is She from?

The Artwork I mentioned: 85765238 on Pixiv (Can’t directly link it, because then YouTube would BONK me Important: If I rember correctly, Old Isin thinks he has seen Kaltsit in one of his dreams, which supposedly show Events that happened years ago I would have loved to discuss that in the video, but sadly the Stages are closed and I can’t re-read the parts where I recall that stuff to be said (I somehow took a Screenshot of EVERYTHING said in this event, but this very scene ffs) Whatever