First the villains and plot for Iron Man 4
The Main villain is speculated to be
Fin Fang Foom
Option A
The film is to be based partially and loosely on the Dragon Seed Storyline of the Iron Man comics
Ben Kingsley is to reprise his role as the Mandarin regardless of Guy Pearce being the villain's MCU version over the tattoos and people using people as mask crap. Marvel should resume with the Mandarin as Trevor Slattery in a Frankenstein's Monster like way except being evil like Aldrich. Instead, Trevor will be more of a rival to Tony simply by dealing with other villains and sinister organizations like AIM with his own methods and by acquiring the ten power rings and by suiting up in black armor, he will be rebranded as Iron Mandarin
First he needs to be broken out by another villain capable of infiltrating places and skilled in martial arts and assassination tactics and the one Iron Man capable of doing that is
the Ghost
With the Ghost debuting in the next film, not only will he be a suitable Iron Man villain adaptable for the MCU. but also with his skills of stealth and martial arts tactics, he should be capable of breaking the Mandarin (Trevor) out of jail and bringing him over to the Ten Rings to explain to him about Tony Stark and Aldrich Killian
and after Raza or who ever is in charge of the band now explains their affiliation with Killian, he will give Trevor the ten power rings that they named their organization after and once Trevor puts them all on and shifts into black armor with the reanimation ring, Fin Fang Foom appears from the site they found the rings at and after showing the dragon the power of the rings, Foom organizes a deal with Slattery and the actor using the rings to put the terrorists under his command he has the world adress him as Iron Mandarin and next they attack AIM facilities all over the US and then Iron Mandarin and Iron Man fight during the Ten Rings seige
and at the end after Trevor completes his deal with the dragon reverting his remaining brothers back to their dragon forms and then the dragons start putting their plan of invasion into action. After realizing the disaster he has done, Iron Mandarin will team up with Iron Man and his allies to defeat the dragons
It may seem strange to some of you but after the mess and the chaos the twist on the Mandarin had caused and for how the Mandarin ended up being an innocent actor being played by a psychopathic scientist on taking the fall for the suicide explosions of Taggert and the rest of his failed test subjects and being arrested without understanding what's going on and being arrested for those crimes when he really never thought people were being killed, bringing him back for Iron Man 4 and evolving him into the real ring powered Mandarin that we really know from the comics would not only make things better but its the right thing to do because that way with him meeting the terrorists in the first film in the upcoming Iron Man 4, we'll be sure to get all the specific confirmation we need on Killian's involvement with him becase Maya mentioning Military contracts and Black mentioning Killian co-opting the band is NOT enough to close this case because it's hard to believe that an american would be the head of terrorists from an enemy country even if they are making the franchise loosely based on the comics.
And how would you expect Marvel Studios to do the rings for the Mandarin without being related to the character's comic book version? Same way they did it for the Cosmic Cube/Tesseract in Captain America: The First Avenger and with Thor's hammer being teased in the second Iron Man film's end credits. For in this case, simply by making both Fin Fang Foom, his dragon race, and the magic rings Asgardian based. It may seem strange but hey since the Iron Man movie franchise is in the same film universe as Thor and the other Avengers that appeared in the Avengers film, it wouldn't be such a problem to have some Asgardian elements in Iron Man 4.
or in case Kevin Feige and Marvel refuse to get Kingsley to reprise his role as the Mandarin despite making Aldrich Killian the character's MCU version then here is
Option B
Fin Fang Foom will be used as a giant mechanical dragon which serves as a combination of him and Ultimo combined
and this picture below is just one example on what Fin Fang Foom would look like in the 4th film
Sure enough, if Kevin Feige is gonna need to try something really new in order to make Fin Fang Foom's Marvel Cinematic Interpretation work out as a giant mechanical menace, he is gonna have to go with at least a few major human villains to work it out including some different resources and technologies and for this kind of thing, the villain that should operate the giant mechanical menace is
The Controller
and the two other villains that should be used as his bodyguards and henchmen are
Killer Shrike
and
The Ghost
and now for Iron Man 5's villains and plot
With Iron Man 5 serving as the last Marvel Cinematic Iron Man film its main villain is most speculated to be
Ezikel Stane as Titanium Man and leader of the Marvel Cinematic version of the Maggia and if you're wondering why he should be the Maggia leader of the MCU it's cause of the goons that his father Obadiah had with him in the first movie that he had executing some of the terrorists
Sasha as Madame Masque
and the other 2 speculated villains avilable are
Blizzard
and
Living Laser
Some of you are thinking of characters like MODOK, but characters like him are not gonna happen because Shane Black, the director of Iron Man 3 was kind enough to invite some of the fans that he along with Jon Favreau, Kevin Feige, and Louis D'Esposito had pissed off rudely with the twist on the Mandarin and explained to them that their reasons for violating the Mandarin and for not doing the magic rings for the character was indeed because they had the Marvel Cinematic Universe tied to our reality and modern day and events and some of the characters like the Mandarin properly as we know him for was because of certain difficulties at handling the stereotypes, you can't expect them to use MODOK when the character's head is so disturbingly ugly and unbearable and besides AIM already had a major role and appearance in Iron Man 3 and because Aldrich Killian was their leader in the MCU, he's very much Marvel Cinematic MODOK enough.
And for why they should still use Fin Fang Foom inspite of tying the MCU with modern day reality? Simple, because they are gonna need something to keep the plot of the next two possible sequels and without villains like Foom, what else are they suppose to do?
To find out what Marvel Studios has in mind stay tuned.