Paradox, Gwen, Young Ben+Gwen+Max, Ben 10k, Ditto, Wildvine... even Pakmar being back was cool.
I can't stress enough how awesome it was seeing Paradox and Gwen again. I actually cheered when Gwen arrived at the plumber base. That weird time-world place was awesome too, it really brought back memories of the old days of Ben 10. Oh, and that young Clockwork looked like the cutest thing I've ever seen haha. I liked the twist in the plan about hiding Paradox's hand as well.
In addition, I love that Omniverse actually attempted some complexity in the story.
I seriously hope those passing acknowledgments about the 'Time War' grow to mean something. I will eat my foot in happiness if they do. If they don't... well, then that makes me dislike the whole ending to this episode. Bringing Ben 10,000 back just for a gag? That is exactly the kind of thing that is turning me off Omniverse, the focus on comedy over story. But yeah, I really hope this 'Time War' actually becomes something!
Only things I definitely didn't like was Eon's voice and that there was no acknowledgement by anyone that Eon is an alt version of Ben ...unless he isn't still Ben? Eh, I feel the same as Grandpa max with this timey-wimey stuff, it's so confusing.
Also, seeing young Ben question Undertown reminds me how ridiculous of a concept it is. Do we know when Undertown actually started down there?
Oh, and anyone else love the music they played when Ben 10,000 stepped through that portal?