To clarify the link between Under the Black Moon and Off-season · 6:51pm Jul 28th, 2021
From the Off-season's point of view:
0. Both books should be okay to read without knowing the other part.
1. Under the Black Moon happened a few (unspecified, but really little. Less than twenty, likely less than ten) years ago.
2. World of UtBM, as presented, lay right there in Off-season, beyond the portal of Littlehorn. The portal is still experimental. The portal was built as a joint effort from both sides shortly after the end of UtBM. It works both ways.