Whoa, Team Rocket actually successfully got the Darkinium-Z?!

Well, color me surprised! I was
not expecting Team Rocket to actually succeed
and to be honest, I was hoping they wouldn't. But in true (read: idiotic) Team Rocket fashion, they didn't do all of their research (even though James created a Z-Crystal detection device), so not only do they have no idea that Z-Crystals are type-specific, but they also have no idea what the poses are for each Z-move (or that the Trainer has to perform the pose alongside the Pokémon). In other words, Darkinium-Z is completely useless to them at the moment.
That focus on Bewear at the end of the episode makes me think Bewear is going to be the one to (eventually) use Blackhole Eclipse (when the TRio eventually figure out how to properly use Z-moves), which means either Bewear is going to be caught, or it's going to be an ally Pokémon who battles under their command. The latter, while far less likely, could potentially be more interesting, as that would enable both Jessie and James to use Z-moves.
Mimikyu was bad*** in this episode!

I didn't expect it to battle so seriously without Pikachu around to awaken its bloodthirsty rage, and it totally did a number on the Totem Raticate.
I like how the focus switched between the Team Rocket vs. Team Skull shenanigans and Ash and his classmates learning about Z-moves and Z-move poses. The focus on Lana's interest in learning the pose for Hydro Vortex makes me wonder if a Waterium-Z is in Lana's future.

Also, the mention of how Pikachu can use Corkscrew Crush and Ash practicing the pose for Corkscrew Crush makes me wonder if the writers are hinting at what Ash's next Trial will be.