It depends on the specific fanfiction. In some stories, Superior Iron Man might be more powerful because he's willing to push the limits of his technology and his morals further. But in others, Iron Man could be more powerful due to his experience and his ability to work well with others.
Thanos could also win in a fanfiction. He has incredible strength and the power of the Infinity Stones at his disposal. In a lot of fanfictions, the power levels are often exaggerated. Thanos could simply use the Reality Stone to make Iron Man's weapons ineffective or use the Time Stone to freeze Iron Man in time and then defeat him. His brute strength alone is enough to overpower Iron Man in a direct confrontation. And his experience in battles across the universe gives him an advantage over Iron Man who mainly operates on Earth.
The differences between them are significant. Lex Luthor is more of a traditional villain in the short story. He is jealous of Superman mainly and wants to prove his superiority through his intelligence and inventions. His technology is sometimes more experimental and untested. Iron Man, however, is a hero who has refined his suit over time. His technology is reliable and battle - tested. In terms of character, Iron Man is more self - sacrificing. He is willing to put himself in danger to protect others. Lex Luthor is more concerned with his own status and power. Their methods of achieving their goals are also different. Iron Man uses his technology to directly combat threats, while Lex Luthor may use more underhanded means like manipulation and subterfuge.
Iron Man would probably win. He has a highly advanced suit with a plethora of weapons and defensive systems. His suit is constantly evolving and he has the genius of Tony Stark behind it. Metallo, while strong with his kryptonite - powered body, Iron Man could analyze his weaknesses and use his repulsors, missiles and other gadgets to take him down.
One interesting plot could be where Metallo somehow gets an upgrade that can disrupt Iron Man's technology. Then Iron Man has to rely on his wits and basic engineering skills to fight back. Another could be a scenario where Iron Man has to protect a city from Metallo without using his full - powered suit, making it a more challenging fight.
One interesting plot twist could be that Iron Man discovers a hidden power within his suit that can counter the Infinity Stones. Maybe it was something he unknowingly built into it long ago.
In an 'iron man vs lex luthor' fanfiction, Iron Man could initially react with disdain towards Lex Luthor. Given Iron Man's own journey of redemption and his attempts to use his technology for good, he would likely look down on Luthor's self - serving motives. As the story progresses, Iron Man's reaction could shift to a begrudging respect for Luthor's intelligence, while still remaining committed to thwarting his evil plans. Iron Man would recognize that Luthor is a formidable foe not to be underestimated, and this would fuel his determination to outwit and defeat him.
In Thor vs Iron Man fanfictions, a really interesting plot twist is when the two are forced to work together against a common enemy. They start off as rivals but then realize that they need each other's skills. Another popular twist is when there is some sort of time - travel or alternate dimension involved. Maybe Iron Man travels to a time when Thor was a young and inexperienced warrior, or Thor finds himself in a dimension where technology is far more advanced than in Asgard and he has to adapt quickly to face Iron Man. These plot twists keep the fanfiction fresh and exciting for readers.
Well, it really depends on how the fanfiction is written. If the story focuses on Iron Man's technological advancements and his ability to quickly analyze and counter Thor's attacks, he might have a chance. However, Thor's raw power is not to be underestimated. He has centuries of combat experience and his powers are magic - based, which could potentially bypass Iron Man's technological defenses. So, more often than not, Thor has the upper hand.