OK, this is so very patchy, but it'll have to do for now! I'll probably be adding to this as I rewatch G1 ;)
Backstory
Established canon for Vortex is patchy, but fascinating.
He was involved in a plot to overthrow Megatron and got caught. The plot itself isn’t specified, but it’s implied in ‘Starscream’s Brigade’ and ‘The Revenge of Bruticus’ that all five Combaticons were in on it together.
Their personality components was isolated and kept in the Decepticon Detention Centre under Shockwave’s control. Starscream broke him and the other Combaticons out, gave them new bodies and combiner programming.
After another unsuccessful attempt to take over, Bruticus was reprogrammed to be more loyal to Megatron. I’ve taken this to mean that Vortex was also reprogrammed, as it doesn’t make sense to me that the components wouldn’t have been affected along with the combined form. Hence, the copter has very strong programming that disallows him from directly acting against Megatron. It doesn’t stop him being an insubordinate glitch, though.
One of the first things Vortex did when Starscream gave him a new body (and after pwning a few Autobots) was get into a fight with Onslaught, indicating a healthy disrespect for authority. Not that this stops him from doing what Onslaught says at other times.
He has good reason to hate Swindle, thanks to the incident in BOT where Swindle sold his team mates for spare parts, and Swindle gives him a mouthful in ‘The Five Faces of Darkness’ after he says something particularly dumb. But apart from that, they all seem to rub along OK. Well, for Decepticons. It’s far from the healthiest team dynamic, but there are elements which indicate that when the worst comes to the worst they will back each other up (and pile into Blast Off so he can get them the hell out of there).
Concerning the parts not covered by canon, I’m going to keep it vague regarding any canon characters, as I don't want to limit anyone coming in as another Combaticon.
Regarding background/stuff that goes beyond canon, the way that Swindle calls his team mates ‘gentlemen’ in ‘The Revenge of Bruticus’ always made me think of them as a crime syndicate. Hence, I think of Vortex as someone who started out in the military - built in a factory for the defence of Cybertron (after the defeat of the Quintessons, but a long while before the war) - but who got out of the military and took on private work during the Golden Age. This was the kind of work that doesn’t require a conscience, and it kept him entertained.
At some point, he got involved with Onslaught and the rest, and they decided to attempt to take over from Megatron. Canon doesn’t specify how long they were in the Detention Centre, but it was certainly longer than the 4 million years that Megatron, Optimus and the rest were in stasis on Earth.
Personality
Vortex is a happy-go-lucky, excitable psychopath, suffering the after effects of several million years in sensory deprivation (for which he was mostly awake and aware). He’s vicious, unprincipled, easily distracted, capricious, cruel and destructive. He can come across as shallow, which he is, to a degree. He craves attention and all kinds of stimulation (from vanilla through to so intense he needs a medic). He hates numbness, and he isn’t greatly fond of people messing around in his processor or his databanks.
The major limitations on his behaviour are the loyalty programming and the combiner programming. And his aim, but he’s working on that.
He doesn’t have a great deal of respect for authority, and if it wasn’t for the inhibiting influence of the loyalty programming (and the deterrent of Galvatron’s cannon), he’d still be plotting to take over.
Sadly for Vortex, strategising isn’t his strong point. He’s a decent liar (sometimes) and a consummate manipulator, but as far as military or criminal strategy goes, he sucks. He needs Onslaught for that, and he knows it.
As he’s taken from cartoon continuity, he doesn’t have a spark. This isn’t the reason he has no empathy for anyone except his team, no one has a spark where he comes from; he has no empathy because he’s psychotic.
The only reason he has empathy for his team mates is because of the combiner programming. Without it, he wouldn’t. He views his emotional attachment to his team as a weakness, but he’s also very deeply invested in the gestalt. Not that he’d ever admit it.
Vortex isn’t above revealing deeply personal information about himself in order to get what he wants. In fact, there are very few things that he wouldn’t do to pursue his own goals and the aims of his team. He has no personal boundaries, but a very keen awareness of the personal boundaries of others. He is sensitive to issues of consent, but mostly because he likes to press peoples’ buttons. Other people are there for his amusement. Unless he’s working, in which case other people are only there for his amusement once he’s done with the interrogation.
Interrogation doesn’t equate to torture for Vortex. He knows what techniques are most likely to yield a good result. Interrogation is work, but as for afterwards, well if a subject has no further use…
Other stuff
Canon doesn’t state what Vortex’s Cybertronian alt or root modes looked like, so for the sake of convenience I’m going to assume they were superficially similar to the form Starscream gives him, but more space age in an 80s way.
His current root mode is
grey with teal accents (who says teal doesn’t go with anything?), to match his weapons (and, apparently, his crotch). I’m going with his cartoon colour scheme rather than his toy colour scheme because I like it more. His Earth alt is a
SH-2 Seasprite helicopter, which has a pretty good turn of speed and excellent manoeuvrability all by itself. Vortex is faster and more agile, but he still can’t match the speed of any of the jets. He’s not jealous, though, he likes being a rotary mech.
He has arm mounted gattling guns, which seem to work as lasers in the cartoon, and a glue gun, which also is a bit more laser-tastic than descriptions on the merchandising might suggest :P
He’d rather like to be able to turn his rotors into swords, like Springer can. This is one of the many reasons he’d love to have Springer all to himself.
Writing samples:
Clicky for third person sample. And first person sample.