But my issue with their treatment of Breakdown is how they introduced him as this guy who was strongly implied to bring with him something substantial to the story, and yet ultimately brought nothing of the sort.
We're introduced to him in episode 10 as Bulkhead's rival, which at first seems kinda cool and promising. We're left to wonder "Why do they hate each other?" And within this same episode Bulkhead gives us the first piece of the puzzle: "[They] have a history."
So now we're left thinking, "Oh neat, let's see where they go with this."
He next appears in episode 11, buffing Megatron's body. A nice little moment of humor and charm that could be a our first look at a less destructive side of him. After all, he is Knock Out's best friend and assistant, so he's gotta have some experience in areas outside of combat, right?
Well, then comes the fight scene where he does just that: Fight. No progression here, but there is still potential.
Episode 14 was his next appearance, in which he just fought the Autobots again. Though, it was Bulkhead that he primarily fought here, so could there be some more bits to their story seen here? Nadda.
Come episode 16 and we finally get some decent exploration into the guy's personality. Or rather, into the surface of it since the most depth we get is when he's shocked to learn that Autobots (rather than Decepticons) were trying to save him, then when he first teams up with Bulkhead against MECH and then backstabs him when Starscream shows up. And there's also the other side of the conflict with Bulkhead being reluctant to save him and only doing so after some misguided encouragement from Miko. While it's all a step in the right direction, we're ultimately given no more about their history or their rivalry than when we first met Breakdown.
Episode 18 was next for Breakdown, in which he was just a typical Decepticon wanting to redeem himself in the eyes of his leader (as any Con would want in his case) and then once more as Bulkhead's dance partner combat counterpart, with anything between the two still going unexplored and undeveloped.
Likewise, episode 21 had him fighting Bulkhead again, and that's it. By now, it's starting to feel like any chances of this guy actually having the implied story arc between him and Bulkhead being looked into beyond "We have a history" are slim to none.
Episode 22 had him once more as ground fodder with a name, though he did at least get one scene in which he admitted having taken an interest in Airachnid. Could this be something to explore with him?
Episodes 26, 27, 28, 30, and 31 had him as nobody special, though he did get a cute gag scene in episode 28. But, let's face it, it was Fowler, not Breakdown, who made that scene fun with his Star Wars reference.
And then finally came his last living appearance in episode 33, in which he was nothing more than a sacrificial lamb for MECH to happen upon. He was killed off before his story could even be told, as all of his previous appearances kept wasting their time getting on it.
And what's more is that it was Airachnid who killed him, and did so because he was trying to kill her. Trying to kill the very same fembot he had previously mentioned having taken an interest in, as though he had never said that at all.
We spent 13 out of 24 episodes with this guy, in which he started off promising but ultimately ended up as wasted material. He came into this show with the seeds for something interesting, only for said seeds to instead keep delaying their growth until they were dug up, cut apart, and burned to ash after having only sprout nothing beyond their roots.
TL:DR - He came in as Bulkhead's rival. We ask "What's the story of their rivalry?" Bulkhead says "We have a history." We say "Alright, so what's their history? And how will their story play out?" Show says "Stay tuned." We stay tuned. He keeps appearing, we keep asking. Show doesn't answer, so we wait and see. Still no answers. Episode 33 happens. We are bummed, for Breakdown turned out to be nothing more than a tease.
And the same could be said about their deciding not to properly conclude Airachnid's story. Her story with Arcee was similarly mistreated.
Episode 12 - Airachnid appears, ticks off Arcee, they fight, Airachnid retreats.
Episode 17 - Airachnid returns, ticks off Arcee, they fight, Airachnid retreats.
Episode 18 - Airachnid returns again, ticks off Arcee again, they fight again, Airachnid retreats again (though, this time is due to her being stuck to Breakdown)
Episode 20 - Airachnid manipulates Starscream, ticks off Arcee, they fight briefly, Airachnid retreats to go after the Immobilizer, she fights the other Autobots, Bumblebee beats her, and she retreats for real this time.
Episodes 23, 24, and 25 - she only briefly appears here and doesn't really do anything
Episode 26 - she tries to overthrow Megatron, but is beaten by Soundwave. None of her story with Arcee here
Episode 33 - Megatron orders her to be killed, but she escapes death and pits Megatron against an Insecticon. Arcee fights her again, Airachnid is shot by Starscream, and Airachnid retreats, this time to an Insecticon hive (how it got there is yet another thing that received no explanation either).
Episode 36 - she sents her Insecticons to attack everybody, Arcee fights her, and then she's put on ice in a stasis pod.
Episodes 44, 49, 53, 55 - she's a nice piece of furniture
Episode 60 - she's freed from her pod, turned into a vampire, dumped on a moon, and never looked into again.
No character growth for her, no resolution for Arcee's thirst for vengeance, no proper send off to Airachnid whatsoever. Just a complete and utter surrender by the writers.