I haven't watched Casshern yet (appalling I know

) so I don't know the story but despite that I could understand what you were trying to show in this video and I loved watching it.

At first I was like "ho-crap, almost 6 mins long?!" but it flew by so quickly (like all the other Casshern videos I've watched) that when it got to the end I was like "WHAT IT'S FINISHED?" XD So yeah I really enjoyed it.
I know you're not looking for criticism, not that I have any actually, to be honest the only thing that looked a bit sketchy to me was the threshold looking transitions near the first part of the video. Otherwise I have no complaints about the editing. By the way I also really loved the overlaying in this.

That was very nice.
I'm sure its overlaying but I haven't seen the show so I can't say with 100% accuracy but whatever it looks good. XD
Also gotta remember to write down reminders to watch this show before another Casshern video gets made. >__>