Carrier Prime

Leader of the Autobots in an alternate universe, she and her Alpha Team came to [whatever mainstream universe you wish, it really doesn't matter] in search of the multiversal bounty hunter Death's Head, travelling through a multidimensional portal system she refers to as a 'Causeway' [see what I did there? I am so clever! 'Causeway' is also the title of the story event] 

Carrier Prime hails from a universe in which she and not Optimus survived the Fallen's secret [and prolonged] genocide of the Primes and became the 'Last of the Primes'. She's basically an alternate universe Optimus, but with some differences [y'know, due to them being different 'bots 'n' all], like her being a little more hot-tempered, but still basically the same character in just as many ways [I.e. THAT MEANS NO SEXUAL DRIVE OR INTEREST!!], shaped by the harshness of betrayal and war, strengthened by the hope an unity of Cybertron's people. She wants her homeworld restored as much as anyone, but refuses to destroy other worlds to do so, resorting instead to saving what's left and protecting her new homeworld, Earth. 

Her weapons are... rather unique. Her blades are sort of a combination of ax heads and hooks, with the added aesthetic of tonfa, energized by her own energon. Her gun is another interesting item, arguably even deadlier; a combination of a flamethrower and a grenade launcher, the shorter barrel fires the grenades, while the longer one spits the fire. This particular fire is a chemical called 'Energon Fire', which not only causes the outer armor -and other components, of Transformers to deteriorate at a much faster rate, but also get into in fluid lines and pretty much torch a bot from the inside. this may or may not have influenced her choice of a vehicle mode with flame decals. Oh, and if you attach a gun belt, it can also shoot regular TF bullets. 

Hey, I did say she has a bit of an aggression problem. She only exerts it in combat, though. 

After her Prime heritage was discovered, she got her name -'Carrier', from how she would haul as many wounded or helpless as she could off the battlefield during the Revolution era, prior to the Decepticons. Fittingly, she transforms into a semi-truck that sometimes pulls a car carrier. 

Anyway;
Both teams of Autobots suspect each other of fowl play at first, but once they find Death's Head they quickly put these differences and suspicions to rest, focusing all their efforts on subduing the bounty hunter. Eventually it comes down to the two Primes and Death's Head... which is hilariously awesome as Optimus and Carrier are bad@$$es and Death's Head keeps spitting out his ridiculous dialogue... in Zurg's voice. 

Finally DH seems to have Optimus cornered and a gun pointed at his head. So naturally he starts talking;
"You thought that you could defeat me. Yes? Your other incarnations could not defeat me. Neither could the Enterprise; nor the Jedi; nor the Doctor; nor the Avengers; nor the Justice League; nor Master Chief and those Red and Blue ones; nor those 'Ninja Turtle' things; nor Princess Twilight Sparkle! Yes! You cannot defeat me, Primes of two Worlds! Yes! For I-!!!" -KABOOM-!

[A grenade detonates behind his head, not killing him, but propelling him a good few yards] 

"-Talk too much." says Carrier, cocking her flamethrower/grenade launcher. 

So anyway, they strap of Death's Head up and Carrier's team haul him through the Causeway, and Optimus and Carrier wish each other a better future for both their worlds. 

...

Some time ago I'd received word about some generic Mary-Sue fan-created Transformer, and so naturally I took no interest and forgot all about it.

But then recently her presence became known to me again [through something to do with her creator getting banned from DA, or something] and I learned her name was Causeway Prime. I finally felt curious enough to Google Image this 'infamous' Mary Suebot... and actually, some of the commissioned artwork of her didn't look so bad. What I saw in the artwork was a whole lot of potential for a very interesting fan-created character...

BUT, her creator stupidly gave her almost no personality and no faults, practically making her Optimus Prime's sex slave. To put it as bluntly as my friend did; "Ew". 

I admit I was torn; on the one hand there was serious potential; but on the other everyone who hated this character had every given right to. So I just let the matter sit while my mind wandered. Finally the idea came to me as I was commenting on the post [that informed me of the updated scenario] and while responding to the response to that, the idea came to me.

My mind is weird. [NOTE: I'd write the whole story myself, buuuuuut if you know me at all, then you know my fanfiction capabilities would only get me the first few chapters before I hit Writer's Block] 

As for the finished piece? Something went up with my scanner and there's no way to eliminate the blue ink I used [next time I use black!] meanwhile, the balance is off and that's my only issue.