this is not a filler arc, this is the consequences of Ainz "taming" Hamsuke without thinking
he broke the forest's power balance and placing the villages surrounding the forest in danger
now he have to make it right and while he's doing it, we get the villager's point of view of how things unfold
and it's also showing us side characters growth (of enri, nifea and most importantly lupusregina)
i have no complaint other than that the pace is a bit too slow for a monthly manga