Unity is a Transformers: Generation 1 fanfic by pink_shoes.
Unicron is rapidly approaching the Earth; while Optimus Prime is determined to defeat the monster planet, he's aware that he'll have a better chance of victory if he's upgraded to be stronger. This upgrade takes the form of giving Prime the ability to combine with another mech, who ends up being Skyfire by process of elimination. Their combined form, Sky Convoy, should have the power and abilities necessary to stand up to Unicron.
The plan (and Sky Convoy) has some hoops to jump through in order to get there, though. Most of them are related to Skyfire's dislike of combat and his ongoing relationship with Starscream. Will Unicron be struck down by the combiner in spite of Sky Convoy's inherent barriers to success?
It can be found here.
Unity contains the following tropes:
- Adaptation Origin Connection: No explanation is provided in the original cartoon as to why Astoria Carlton-Ritz is a Walking Techbane. The fic attributes her powers to her status as Unicron's Herald.
- Brick Joke: Partway through the second chapter, Perceptor consumes two cubes of high-grade energon in rapid succession in order to deal with his colleagues arguing. At the end of the chapter, Optimus Prime notes that Perceptor is passed-out drunk.
- I Need a Freaking Drink: Perceptor's response to Ratchet and Wheeljack descending into an argument is to down two cubes of high-grade energon he was saving for an emergency.
- Ironic Echo Cut: Skyfire decides to run Wheeljack's "make a combiner to fight Unicron" idea past Optimus Prime in spite of the potential security concerns, reasoning that "the worst he can do is say no". The next line cuts to Megatron saying no; Prime liked the idea enough to ring up the Decepticons to see if they'd be on board with it.
- Lampshade Hanging: The overall goofiness of the fic and its source material is poked fun at when Megatron is unsure whether he's imagining an uptick in strange events following the Cybertronians' awakening on Earth.
- Obfuscating Stupidity: Unbeknownst to the majority of the Victory's crew, Rumble and Frenzy's childish behavior obscures how mature they actually are. Their judgement alone is sound enough that Megatron usually believes what the duo has to say.
- O.O.C. Is Serious Business: Cosmos is usually cheerful and fond of practical jokes. When he sends a live feed of the Unidentified Astronomical Object back to Earth, he's noted to sound unusually on edge and states that the transmission depicting Unicron isn't a prank.
- Pluto Is Expendable: Midway through the story, Pluto is eaten by Unicron. Red Alert is subsequently puzzled by how much humans care about the dwarf planet and the increase in hate mail the Autobots are receiving after they announced its destruction.
- Pragmatic Villainy: Megatron decides to leave the Sky Convoy project alone because interfering with it has no benefits whatsoever for the Decepticons. If the combiner succeeds in destroying Unicron, they'll still have access to the Earth's resources; if it fails, they can easily retreat to Cybertron before the monster planet arrives. He even indirectly helps the Autobots by not telling Starscream that Skyfire is part of Sky Convoy, as his second-in-command is on good enough terms with Skyfire to convince him to not merge with Optimus again. As the Autobots lack a backup plan, this would force the Decepticons to either go home or perform an Enemy Mine with the opposing faction to fight Unicron neither possibility of which Megatron finds appealing.