First of all, I'm a little sorry if my English is a little strange because I don't understand English. Also, please understand if this seems like a long post. A lot of amazing things happened in episode 21. First of all, Frieren destroyed the barrier that Serie had created. The flag was up but... I never thought something like that would be possible. Even though the reason was because he was a friend, I thought Frieren was kind because he did it for Kanne. Then, with the help of Kanne's water magic and Lawine's help, they defeated Richter, who was a higher-ranking mage. Up until this point, I had thought that Denken was a good person because he was intelligent and told Richter to stop killing, so I didn't have a bad impression of him. But that didn't mean I liked Denken. But I started to love Denken in episode 21. Even if Denken loses to Frieren, once he runs out of magic power, he fights with punches and doesn't give up until the end. I liked his greed and personality.
A small annoyance in this chapter, when Richter raises the ground, the girls can simply fly away and go near water 😂 And since his attacks rely on raising the ground in several shapes, they can just avoid all attacks by levitating a bit.
I thought about this too. My headcanon was that all Richter had to do was isolate them from Frieren so Denken can try his best against her. So he just raised the ground way above the height of typical mage aerial battles. Sure they can leave to get water but then they're just further away from Frieren which is Richter's main goal.
Remember back a couple episodes. Manipulating standing water as opposed to "loose" rainwater is a lot harder and since everyone here is flying using the same repurposed demon spell the girls wouldn't be able to get much prep time distance.
Well flying and levitating consume mana heavily,even fern and frieren have limited time using them let alone the girls. Flying,offence and defence will drain mana quickly meanwhile richter is just standing there casually manipulating sand 😂