Rick and Morty set the stage for the series' next major villain with the final episode of the fifth season! Season 5 of the Adult Swim animated series made a point of focusing the majority of its run on episodic, non-committal adventures but completely turned things around with the final episodes. The final three episodes not only answered some of the biggest questions fans have had about the series as a whole, but also greatly changed the status quo of the series going forward. This includes setting the stage for a major new potential threat coming in the future.
The final episode of Season 5, "Rickmurai Jack," accomplished several major things for the series' future, and the first of which was finally revealing what Evil Morty had wanted all along. With this reveal, and the final moments of the episode, it seems like the series is tabling this series foe for now. But while this is the case, there's actually seeds planted for the next major foe that Rick will have to overcome. Not outside of the Central Finite Curve, but in it actually as the Rick who killed C-137 Diane and Beth is still out there somewhere.
The final episode of the season revealed what Rick referred to as his "crybaby backstory" and with it had confirmed a few things for fans. Not only did it reveal that the brief flashback we had seen of Diane and Beth being killed by another Rick back in Season 3 was the real thing (which was further confirmed by the reveal that Rick's original Diane and Beth were dead in the eighth episode), but it expanded on this to reveal that this had inspired Rick to explore the multiverse in the attempt to get revenge on the specific Rick that had killed them.
We see in the flashback that his journey through the multiverse led to killing a large number of Ricks, even to the point of forcing a truce between all of the Ricks and forming the Citadel as a result. The only thing is, Rick was never able to get his revenge on that Rick that killed his wife and daughter. So while it's not necessarily a tease that this other Rick will be a season long villain (as this series doesn't really do that kind of thing), it's the kind of tease that is ripe for a follow up in the future.
The finale might have opened up Rick and Morty to a whole new multiverse of threats that are stronger and smarter than Rick, but the biggest tease is the threat that's far more personal. One that this newer, more emotionally open Rick will be even more vulnerable to than ever before. But what do you think? Let us know all of your thoughts about it in the comments! You can even reach out to me directly about all things animated and other cool stuff @Valdezology on Twitter!