Frieren is probably the best use of music in the anime i have seen. The goddam genius way it hypes the situation is amazing, especialy when you contrast this with a very calm tone this anime usualy has. Also the fact that actual amount of important fights is fairly limited makes it that much better. The fact that pretty much every character that shows up for more than a few minutes is designed like a main character in its own story is something i wish more anime/manga/lightnovels would do. Its frankly speaking kinda amazing that you could reasonably make a completley new anime out of nearly every character that was in more than episode and it probably wouldnt even feel like side story ( like most others do ). Frankly speaking its just an artistic marvel.