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.
I'm not sure specifically about Loki x Thanos mpreg fanfiction. Fanfiction can cover a vast range of pairings and themes, but this particular one might be quite rare or not very mainstream. You could try searching on some large fanfiction platforms like Archive of Our Own to see if there are any works of this kind.
Well, it could be something like Thanos becomes intrigued by Loki's legs for some strange, otherworldly reason. Maybe Loki has some sort of magic or power that is centered around his legs that Thanos wants to possess or control.
Power is a common theme. Both Thanos and Loki are power - hungry in their own ways. In fanfictions, they often either compete for power or try to use each other's power for their own goals. Another theme is redemption. Sometimes Loki is seen as a way for Thanos to find redemption, or vice versa.
A possible plotline is that Thanos hears about the powerful chakra in the Naruto world and decides to conquer it. Naruto stands up to him, and during the fight, Naruto unlocks a new form of his power that is on par with Thanos' strength with the Infinity Stones. Along the way, Naruto teams up with some of his old foes who also realize the danger Thanos poses. They all fight together to protect their world.
One possible plotline could be that through some magical - technological mishap, Tony Stark ends up in the Harry Potter universe and somehow becomes pregnant. Maybe he has to deal with the magical world's reaction to this very un - magical situation while also trying to find a way back to his own world. Another could be that a spell or some new technology allows for a cross - universe connection that results in the mpreg situation, and then it's about how the two characters from different worlds navigate this new reality together.
Well, perhaps in this fanfiction, Loki is cursed to be attached to Thanos' legs for a period of time. This forces them to work together in a very strange way. Loki tries to use his wits to find a way to break the curse, while Thanos is frustrated by Loki's constant attempts at trickery. Along the way, they might encounter other characters from the Marvel universe who are both amused and confused by their situation.
One possible plotline could be Loki's journey of self - discovery. After being abandoned as a child, he might struggle with feelings of unworthiness. Thor could then play a role in helping Loki realize his true potential. Maybe Loki initially resents Thor for having a more 'normal' upbringing, but as the story progresses, they come to understand each other better.
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.
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 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.