The first ten episodes ("Thundercats Ho" 1-5 and "Mumm-Ra Lives" 1-5) are obviously locked in place. After that, I suggest "Together We Stand" as the first episode after the Lunataks' debut five-parter. In this episode, Mumm-Ra decides to launch an assault on the new Thundercats, i.e. the "Tower of Omens" Thundercats, i.e. Bengali, Lynx-O and Pumyra, as the first part of a plan. He chooses the Berzerkers as his army (not the Mutants or the Lunataks). This strikes me as intuitive on his part, given that the Berzerkers were the only group who have actually succeeded in beating those same three people (back in "Thundercats Ho" Part One). Since the first episode after the two movies/five-part epics should be somewhat introductory of the new status quo that those movies extablished, I think "Together We Stand" works well. It not only establishes the Tower of Omens and the new TCats, but the new weapons for the three of them get a lot of play: Lynx-O uses his light shield to try to signal Cats' Lair; Bengali has a whole speech -- "Hammer of Thundera, don't fail me now!", or some such -- when he first uses his weapon; and Pumyra does some schtuff with her thing, which I do not know the name of. In the second half of the episode, Mumm-Ra brings in Luna. I don't remember their initial dialogue, but it struck me as appropriately prickly given how "Mumm-Ra Lives" ended. It also seemed like a good episode to, again, establish the new status quo (i.e., moving forward, the Lunataks would end up being the default go-to henchman for Mumm-Ra (with them replacing the Mutants in this regard). Again, I like that this episode kind of plays with the question of whether it might be the Berzerkers, but after they fare less well than the Lunataks in this episode, the pirates kind of lose their shot at being Mumm's new go-to guys. Granted, the Lunataks don't do terribly well in this episode either, but they do manage to take over Cats Lair, BAM! in like two seconds (off-screen!), and that feels right to me, given that they are set up in "Mumm-Ra Lives" as being a way more threatening force than the villains that preceded them. I also like that after they take over Cats Lair, they want to put a giant moon on the chest of the Lair, in place of the TCat logo. (A detail that really makes me smile.) I guess I put that "Moon" moment in the same category as the big intro of the new TCats' weapons: It's sort of an introduction/consolidation of the the new villains' logo/"brand," for anyone who missed the big five-parter. (Sidebar: As a big fan of the Luntaks and their introductory five-parter, I really hated how quickly they devolved into another set of clowns, the same way the Mutants did over the course of Season One. So another reason I like "Together We Stand" as the first episode post "Mumm-Ra Lives!" is that it shows the Lunataks as still being somewhat threatening and dangerous. I don't like that it ends with them being dispatched so easily, but I guess that scene is kind of the "hinge" by which the Lunataks swing from awesome bad-@$$es into wimps ...) Whew! Sorry, I probably could have gotten my point across with less words, but there it is. That's my argument for placing "Together We Stand" as Episode 11.