Another plotline could involve Loki's control over Percy being a part of a larger plan to take over a realm or defeat an enemy. Loki might see Percy as a useful pawn in a much bigger game. He could use Percy's skills and connections to infiltrate places or gather information. Meanwhile, Percy could be fighting against Loki's control internally, trying to break free and save his friends and the world from Loki's schemes. This internal struggle could add a lot of depth to the story.
Perhaps Loki controls Percy to gain access to certain powers or artifacts that Percy has access to. Since Percy has his own set of powers related to water and being a demigod, Loki might see an opportunity to use him to get his hands on something valuable. This could lead to a series of adventures where Percy is being forced to act against his will while Loki manipulates the situation from behind the scenes.
One possible plotline could be Loki using Percy for his own mischievous ends. Maybe Loki wants to cause chaos in Percy's world, so he takes control of Percy and makes him do things that disrupt the normal order, like causing trouble at Camp Half - Blood.
A possible plotline could be that Loki, being his mischievous self, accidentally gets transported to the world of Percy Jackson. Percy at first is suspicious but then realizes Loki can be an ally. They join forces to stop a powerful dark force that threatens both their worlds. Maybe this dark force is a combination of Greek and Norse mythological evils that only their combined powers can defeat.
I'm not sure of specific 'Percy controlled by Loki' fanfictions off the top of my head. You could try searching on popular fanfiction websites like Archive of Our Own (AO3). There might be some interesting stories there that explore this unique concept.
A plotline might involve Loki and Sif coming to terms with their relationship while dealing with the pregnancy. For example, they could have had a rocky relationship before and the pregnancy forces them to re - evaluate their feelings for each other. There could also be a plot where they have to protect the unborn child from some sort of threat, either from within Asgard or from other realms.
A common plotline could be Loki using the marriage to gain power in Laufey's realm. He might manipulate situations to his advantage while also dealing with his feelings for Laufey. Another could be a story where Laufey is the one who has an ulterior motive for the marriage, like using Loki to get closer to Asgard.
Tony might try to help Loki break free from the control. This could lead to a new alliance between them, which would be quite different from their usual relationship. They could then team up against the force that is controlling Loki.
In a Loki x Thanos mpreg fanfiction, a potential plotline could be that the pregnancy is part of a prophecy. Loki and Thanos have to deal with the implications of this prophecy, whether it means the child will bring great power or destruction. There could be a lot of internal struggle for Loki as he contemplates his role as a soon - to - be parent, especially considering Thanos' nature. And Thanos could be using the situation to gain an advantage over his enemies, all while trying to protect Loki and the unborn from those who would oppose them.
Well, a plotline might start with Loki arriving in the Harry Potter universe for some reason, perhaps fleeing from his own troubles in the Marvel universe. He then falls in love with a wizard or has some sort of magical encounter that results in Harry's birth. As Harry grows up, Loki could be constantly trying to balance his own nature of chaos and the need to protect Harry. There could be a conflict when the wizarding world discovers Harry's mother is Loki, and they are suspicious of Harry because of Loki's reputation. Also, Loki could be involved in the fight against Voldemort in a very unorthodox way, using his unique skills.
Maybe Shield has a new weapon that they are testing and Loki becomes an unintended target. This weapon could be something that disrupts his magic, causing him internal pain as his powers are connected to his very being. They might not fully understand the extent of the harm they are causing at first, but as Loki starts to show signs of distress, they have to decide whether to continue or stop.
One possible plotline could be that Harry discovers his true parentage as Loki's son and has to deal with the shock and confusion. He might then start to explore his new - found heritage, learning about Norse magic and mythology. Another plotline could involve the wizarding world's reaction to this revelation. They might be suspicious or even afraid of Harry's new connection.
Perhaps fem Harry has visions that are related to Loki's past or future. This could cause her to seek him out. As they meet, they start to understand each other better. Loki, being the trickster, might initially be skeptical of her seer abilities but as time goes on and her visions prove accurate, they form an unlikely alliance. They could then be on a journey to either change Loki's fate or prevent some great disaster that Harry has seen in her visions. This could involve battles against other magical or mythological beings.