There is so much to say about the second season finale of Star Wars Rebels that I hardly know where to begin. Called "Twilight of the Apprentice" it may be thus named because we've just seen the swan song of one of my favorite characters: Ahsoka Tano (Anakin Skywalker's one and only padawan), which has been an epic seven-year arc if you consider the character was created in The Clone Wars with the sole intent that there would be a showdown with Darth Vader at some point in a blazing lightsaber battle to the death.
The other thing that came as a real surprise to me was the appearance of Darth Maul again. Now going by Maul (how he survived a lightning storm battle with Emperor Palpatine is beyond me, but then again, this is the same guy that survived being cut in half by Qui Gon). Maul lured Ezra to the Dark Side so easily it wasn't even funny. I like to think that it was written this way, because Star Wars Rebels is a television show on the Disney channel with an audience (target group) around thirteen or fourteen years old. But literally, Ezra had became fully engaged with the Dark Side of the force basically in the time it took to ride two elevators to the top of a pyramid. Enough at least that he was able to open a Sith holocron all by himself by show's end...something that only a Sith is supposed to be able to do.
This revelation leads me to conclude that (in recollection of the events we saw in episode VII) either Ezra Bridger or Darth Maul might (in fact) be Supreme Leader Snoke (whom we saw in the chair overlooking Kylo Ren in the movie). It seems fairly simple to assume Snoke could be either of these two. If Ezra Bridger were Snoke, it would explain his fascination with Luke Skywalker because he faced his dad in combat and Luke's dad destroyed his first lightsaber and basically opened his mind to the true power that the Dark Side possessed because Ezra saw him kill Ahsoka Tano. It also could be that Ezra (as Snoke) just wants to kill Luke Skywalker because he wants revenge against Vader (who happened to be Luke's dad). There was also the bit of foreshadowing when Ezra picked up a lightsaber that looked a lot like Kylo Ren's, and Maul did name Ezra "my apprentice" and kept stressing how there was always "two" in a Sith relationship (no more no less). So the path to Ezra becoming Snoke could be as easy as 1) Ezra killing Maul, and 2) then taking Kylo Ren as an apprentice at some point in the future (before the events of episode VII).
Looking forward to season three. That season two finale was pretty darn incredible.