Star Wars: Rebels was the little show with a lot of potential and in the first two episodes of its second season it really lives up to that. Right off the bat the show has a maturity about it that was lacking in the first season, in much the same way that Star Wars: The Clone Wars eventually realized that it had an adult audience it could play to as well as a youth audience and the idea, stories and performances became more complex, so is the way of Star Wars: Rebels. A bit of irony does spring from the fact that this maturation comes from adding in characters from The Clone Wars, but more on that in just a bit.
"The Lost Commanders" and "Relics of the Old Republic" both serve as expositions dumps (through Kanan, voiced by Freddie Prinze Jr.), for the writers to bring aspects of Legends (formerly the Extended Universe), into the current continuity. Much of the drama in these two episodes circles around Kanan's mistrust of the Clones, something not understood by Ezra because he did not read the Marvel tie in comics, as Dee Bradley Baker returns voicing Captain Rex, Commander Wolffe and Gregor.
The writers have done an excellent job in "The Lost Commanders" and "Relics of the Old Republic" in giving Kanan a humanizing moment and the chance to grow while at the same time offering something like redemption to these Clones who were last seen slaughtering the Jedi. The episodes aren't dark and dour by any stretch of the imagination, though tonally they resemble the final season of The Clone Wars more than the first season of Rebels.
Something else that "The Lost Commanders" and "Relics of the Old Republic" hint at is further development of the secondary members of the Ghost's crew. Despite the fact that Hera (Vanessa Marshall), is left aboard the ship to make repairs she gets a good chunk of screen time in the two premier episodes and the responsibility of not being detected by the entire Empire lands squarely on her shoulders. It is to the credit of the writers and of Marshall herself that despite the fact that Hera is often sequestered from the action, she is often one of the most pivotal members of the Rebels crew.
Sabine (Tiya Sircar), however, doesn't have a lot to do in these premier episodes, although neither does Ezra (Taylor Gray), as most of the drama focuses around the mentor characters, the return of the Clones and the introduction of a new mechanical threat from the Empire. Despite this, the episodes never seem lacking and viewers feel assured that there is more to come for these two characters.
The best moment of the Star Wars: Rebels season 2 premiere episodes is the final moment. Ahsoka (Ashley Eckstein), remains awesomely a part of the cast, though in a secondary capacity. This is a great move in both including a fan favourite character in the latest television incarnation without having her take over the narrative and swivel focus away from these new individual characters. Throughout the episodes she proves herself a capable leader and Jedi (a nice move having a female character in charge), and is the pivot point for world building by sending the Rebels crew out to the final the aged Clones in the first place.
"The Lost Commanders" and "Relics of the Old Republic" have struck a great balance for this show. They come out with their best foot forward, bring back something that long time Star Wars television fans are interested in, highlight different aspects of the current crew and look really, really good doing it. If these two episodes herald the shape of this show to come, then it is no great leap to think that Star Wars: Rebels will be remembered as fondly by the fandom as The Clone Wars.