I was also thinking at the end, this was really a bit different than previous seasons of FMP! Even if we ignore FUMOFU, the series up to now has been something of a balance of comedy and action. This season was really pretty relentlessly dark from beginning to end. Not that FMP! hasn't done dark before (the scene in The Second Raid where Sousuke killed Gauron in cold blood when he thought Gauron murdered Kanami) but it never seemed as overall dark before.
You think THIS season is dark? It gets darker. There is no more screwball stuff. That was just a trick to make you love the characters and flinch every time one of them gets kicked in the balls. It is just a spiral downward into the secrets of the Whispered and the horrible heart that beats at the center of their reality.
Fortunately, it seems like they covered three LNs in this last season, so the next season should take us all the way to the end as there's only three more in the main series...
...Which I'm sure is scheduled to come out in 2024. >:D
So far this season I'm in the same boats as most of you - Overlord III, Cells at Work, and High Score Girl. I binged the Overlord novels last month so it's still fresh on my mind to see the differences in presentation.