I like how all the major villains in the series got closure:
- Utrom Shredder, still exiled on the ice asteroid. May be frozen or dead by now
- Demon Shredder, he is killed
- Cyber Shredder/Viral, defeated in the finale
- Mystic Foot, they were killed in the Ninja Tribunal
- Karai, she has left the Foot and turned to good
- Dr. Chaplain, he is Karai's possible husband now
- Bishop, became president of the Earth in FF and is good
- Baxter, reformed in FF and will get a new body off-screen
- Hun, got the crap kicked out of him by Cyber Shredder
- Khan, defeated and most likely sent to jail at the end of the ep
- Rat King apparently is still in a period of figuring himself out
- Sid, reformed and turned to good
- Ultimate Ninja, now a boy with his father
- Draco is dead
- Savanti was killed by that lightning bolt in the prehistoric
- Zangramon/General Blanque in jail and Traximus reformed the Triceratons
- Nano is part of the Justice Force
- Garbageman...hopefully dead at the bottom of the sea...lol!
- Touch and Go, just mercenaries, were defeated in last appearance
- Jammerhead and Triple Threat went to jail.
- Inuwashi Gunjin reformed and became good
- Shokonobo is dead
- Torbin Zixx just cons people in the future, shady but not a true villain
- Zukko, just a mob boss the Turtles defeated
- Viral, see Cyber Shredder
- We can also assume Serling gets sent back to Cody off-screen at the end of the episode.
- The 3 Shredder's is apparently an alternate universe, or at least we can say that for the time being.
- The Elite Guard were disbanded, although Khan was likely one of them.
- The only thing that is left hanging is Darius/Dark Turtles in the future.
Well I will say they handled the villains nicely in terms of closure.