The Perfect Decepticon
While the joint Autobot and Decepticons dedicate the new Trypticon Plaza, Astrotrain suddenly comes crashing to Cybertron and warns them "he's coming, they're coming", someone much worst than Megatron and shuts down. The Cybertronians quickly goes on the defensive, raising the planetary shield, but the "Perfect Decepticons" easily teleport through it. Surprisingly, they don't attack anyone on Cybertron, they're busy fighting each other. One of them, calling himself Tarn, explains when Megatron created them, he made them to be perfect soldiers, mindless soldiers only programmed to fight. Without anyone left to fight, they ambushed Astrotrain in retribution for their fallen leader, and then turned on each other. After the Autobots efforts to contain them fails, and the Decepticons weapons prove ineffective, Tarn says he's heard of the Cortex Helm, which may allow them to change the Perfect Decepticon's programming to get rid of their need to fight.
Seeking out Thunderhowl, he leads them to one of Oynx Prime's hidden islands where the Helm is located. Tarn of course betrays the group once they arrive and claims the Cortex Helm for himself, making the others into his own personal army. Teleporting to a gladiator ring, he forces Optimus to fight, and declares the alliance between Autobots and Decepticons over. The Autobots regroup, and with a teleporter Wheeljack grabbed from a soldier, they're able to get the drop on Tarn. Tarn orders the Decepticons to attack, but the Decepticons refuse to follow him, and stand by the Autobots. The Perfect Decepticons still prove too much for even the joint Autobot and Decepticons, but Soundwave is able to take the Cortex Helm to reprogram them, and sacrifices himself with a massive sonic blast, taking out Tarn with him.
The Autobots and Decepticons hold a wake for Soundwave. Outside the bar, Optimus, Bumblebee, Hot Rod and Windblade have a short converstation, not sure what to do with themselves with the war over. Optimus decides Cybertron is no longer in need of a Prime, that they've all proven themselves capable leaders, while he will finally take the opportunity to relax.
Largely, this episode follows up the events from the season 3 finale, explaining what became of the so-called "Perfect Decepticon" army from the alternate timeline. I'm a little disappointed the episode doesn't explain what became of Megatron-X. Last we saw, Astrotrain had taken him to keep him prisoner traveling through the multiverse. I'd have to assume with Astrotrain's apparent death, Megatron-X perished as well, but it felt like the writers forgot about this plot point.
I wish there was something that explains why Tarn is any different from all the others. While all the other "Perfect Decepticons" were mindless soldiers with no names, what made Tarn decide to think for himself, and give himself a name? Why did he think he should be the new leader after Megatron? The only thing that really differentiated him was a missing arm, and a cut through his facemask and torso (which begs to question how he's so damaged when all his 'brothers' are shown to be nearly invulnerable)... But the episode itself doesn't bother to offer any possibilities for how/why he acts any different.
Not a bad episode, for the most part, but like so much of the series, it just feels like they could have fleshed some things out more..