https://twitter.com/akiyayukie/status/894203333656821761
I don't know if it's enough to put off the presumed tags but Yukie confirmed that Ebata did almost everything on this episode.

How common is it for one person to animate so many scenes in one episode?
Such amazing work.

dash56 said:
How common is it for one person to animate so many scenes in one episode?
Such amazing work.

Actually,it's even possible that he was supposed to animate everyhting but they didn't have enough time.

And solo episodes are not uncommon, some examples including Erased, Sansha Sanyou, Shigatsu wa kimi no Uso, Occultic:Nine, Yama no Susume, Mob Psycho 100, etc, etc.

That bit at the end with the sword breaking and the two of them seemingly stabbing each other (and most of the fight for that matter) seems very inspired by Yutapon's fight from Sword of the Stranger. Considering that this was done on a TV series, on an episode where Ebata also did a lot of the rest of the key animation, it's quite impressive.