Seems universally agreed that the animation this episode was tragic. Like, forget the dragon mouth flapping like it's a wind-up toy, they didn't even bother to spend more than 10 minutes drawing it here:
Almost all the Dragon's movements were super janky. The special effects helped bandage the situation but definitely were not enough. Still I imagine it's an issue with the medium moving from LN to animation and the studio just not being able to handle anything more grandiose with the time and budget they had.
Marcus's last words were appreciably pathetic. "You're going to do the same evil thing you got mad at me for?" "Duh, I'm the Demon Lord." The moments of reflection with Machina at the end were descent enough. The love confession didn't even feel forced!
One thing I did really enjoy this episode though was the audio production. The music is great. And the epilogue during the credits felt REALLY good all-around. Makes me interested to see where they go now that Marcus is defeated.