So many things to comment on, lets do this in order:
1) This ark feels like the ending to the main story, they should have explore more the relationship between Kogarashi and his master before jumping in the whole "truth about Yuuna ark" that way more crazy anthics could have happen and more characters could have develop, sure Yuuna's regrets are the last straw but even that can hold a series forever.
2) Why the f*** did it have to be tentacles??
3) Main villian forgets his main goal and do horrible things troupe confirm. The fact that he has the ability to create clones and not able to cure her illness is THE most unbelivable thing so far... and that a lot considering this series material so far.
4) Seriously though, was there any doubt remainning that Kogarashi would just appear in the Tenko world without effort and make do of the main threat in just one punch?