The episode introduces significant lore regarding the series' antagonists:
The rich colors, lighting, and "epic" powered-up forms of the demons (specifically Marbas and Naberius) continue to be the show's strongest visual assets. Nokemono-tachi no Yoru - Episode 6
“This series was always conceptually interesting, but it really has been creeping up as to the amount of affection I have for it. After the last couple of episodes this is now in my (growing) top tier for the season.” Reddit · r/anime Nokemono-tachi no Yoru - Episode 6
Reviewers noted that while the animation quality for action scenes isn't always revolutionary, it is "satisfactory" and "stellar" during the core demon fights. Nokemono-tachi no Yoru - Episode 6