Season 5 is the last complete series of the Clone Wars and it is one of the strongest. Spoiler alerts as always.
The first storyline deals with Ahsoka, Anakin, Rex and Obi-Wan training a group of insurgents on the Separatist world Onderon. These episodes really excited me for a number of reasons:
It introduces a direct link to Rogue One – a young Saw Gerrera – who is already the most militant in the insurgent band, and whose malice for the Empire is grounded in tragedy;
Hard to miss the subtle and not-so-subtle analogies with contemporary politics, with radical action, terrorism, and tactics in war coalescing into a great storyline
It’s Ahsoka-centric and I have become an Ahsoka stan; including a romantic storyline with Lux Bonteri (dreamboat)
There’s another storyline involving the training of Younglings by Ahsoka and Yoda. The group of Younglings travels along through a few episodes… They seem designed to be cute and sweet, like the Wookie kid. But… that’s pretty dark given what happens to all the Younglings in Episode III. Its a recurrent theme in Clone Wars, the jarring happy-go-lucky affect of the show matched with the darkness of the subject matter and the extreme darkness of what we know is to come vis-a-vis just about every character in the show.
There’s an odd but fairly hilarious droid-centric “D-Squad” mission, where the droids are led by a diminutive lobster thing called “Colonel Gascon”, who has the hubris and ego of a British Field Marshal circa 1916. Again, its sort of weird that there’s this group of clearly sentient droids treated as automatons by their commander, but they win him around in the end after a series of adventures.
Then we’re back in Mandasnore, where Maul and Savage have taken over with the help of the galaxy’s criminals. This is probably the strongest of the Mandasnore episodes, drawing together the threads of the (voluminous) stories about that planet, and wrapping up (tragically) the story of Obi-Wan and Satine (well, perhaps not everything has been said about that tryst…)
Finally, we get to the Ahsoka-leaves-the-Jedi plotline. This snuck up on me, which is pretty silly given that she clearly wasn’t around in Episode III. But nevertheless, it shocked and saddened me. We get some good Admiral Tarkin time in the course of Ahsoka’s murder trial; and some good Asajj Ventress time as well. Disillusioned, Ahsoka leaves. Its handled well, and there’s some suggestion by the writers that the Jedi Council’s betrayal of Ahsoka is one of the factors that leads to Anakin’s disenchantment with how it operates, which Sheev so ruthlessly exploits in RotS.