Maybe the plot could be about Tony and Howard competing to create the most advanced technology. They both want to prove themselves as the better inventor in the Stark family. Along the way, they encounter various challenges and enemies who are after their technology. But through it all, they learn to rely on each other and their brotherly bond grows stronger. This could also involve some cameos from other Marvel characters who are either helping or hindering their progress.
Well, it could be a fanfiction that delves into the emotional side of their brotherhood, showing how their bond influences their decisions and actions. Or perhaps it's a story with a twist, where their relationship leads to unexpected consequences and challenges within the Marvel world.
One possible plot could be that they discover they are brothers in a very unexpected way. Maybe some ancient Asgardian magic reveals the truth. Then they have to deal with their different worlds colliding. Tony has his high - tech world in Stark Industries, while Loki has the magical realm of Asgard. They could struggle to understand each other at first but then learn to use their combined skills to fight a powerful villain that neither could defeat alone.
One idea could be a story where Tony discovers a hidden diary of Howard's that reveals secrets about his early inventions and the true motives behind some of his actions. This could lead to Tony having a new perspective on his father and his own work.
In a fanfiction where Tony Stark is Howard's brother, it would be interesting to see how the family drama plays out. Tony is known for his rebellious nature, and as Howard's brother, he might have butted heads with him more directly. Also, this could mean that Tony would have been around during Howard's more secretive projects. He could have been a part of the team that worked on the Tesseract research, which would have given him a different perspective on things like Hydra's infiltration. It would be a whole new take on the Stark family history.
The portrayal of abuse involving Tony Stark and Howard in fanfiction is quite diverse. Some stories might touch on it to add depth or drama, but not all do. It's really up to the imagination of the fanfic writers.
Perhaps the plot could start with their unusual upbringing. Harry grows up with the Dursleys while Tony has his own issues with his father. They both develop their unique skills. When they meet, they realize they are brothers. They then start to combine magic and technology. For example, they could use magic to enhance Tony's suits or use technology to create new magical artifacts. Along the way, they face challenges from those who oppose the mixing of these two very different worlds, like some traditional wizards who don't trust technology and some tech - moguls who fear magic.
One possibility is that the Avengers are facing a threat related to some old Hydra experiments that Howard Stark was once involved in. They meet him to gather information about the experiments, like the location of hidden files or the identities of key Hydra operatives from that time. Howard Stark, being the brilliant mind he is, joins forces with the Avengers to stop Hydra's resurgence.
Maybe a fanfiction where Tony discovers hidden secrets about Howard's past that change his perspective on their relationship. It could have elements of intrigue and emotional depth.
Pepper Potts can also be a great addition in some of these fanfictions. Even though she's mainly related to Tony, her presence can add a different dynamic. For example, if the fanfiction is about Tony dealing with Howard's legacy, Pepper can be the voice of reason, helping Tony see things more clearly. She can also interact with the memory or apparition of Howard in some creative ways, which makes for a great read.
One possible plot could be that Tony Stark, while on a solo space exploration mission, stumbles upon the Ravagers. He initially has a tense encounter with them as they are skeptical of his motives. But then, they realize his tech can be useful. They team up to take on a common enemy, a powerful alien warlord who has been raiding planets for resources. Tony modifies some of his Iron Man tech with Ravager tech he discovers, creating a new and more powerful suit.