Another possibility is that Loki teams up with other characters. He could form an alliance with the Avengers or some other powerful beings in the universe. Together, they could come up with a plan to stop Thanos. Loki could contribute his unique skills, like his ability to shapeshift and infiltrate Thanos' ranks, and then they could launch a coordinated attack.
Loki could also show signs of fear, though he would try to hide it. Inside, he knows the power that Thanos wields. But on the outside, he would maintain a facade of bravado. His reactions would be a mix of his natural cunning and the instinct to survive in a very dangerous situation.
One great Thanos x Loki fanfic is 'A Meeting of Titans' which explores an alternate universe where they form an unexpected alliance. It delves deep into their complex characters and the power dynamics between them.
Power is a common theme. Thanos is extremely powerful and Loki is always seeking more power, so fanfics often explore how they interact in terms of power - whether it's a power struggle or a shared pursuit of power.
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, one possible plot could be that Thanos uses his mind - controlling powers on Loki to make him steal powerful artifacts for his collection. Loki, being under Thanos' control, has to go against his own nature at times. For example, he might have to target Asgardian relics that he would otherwise protect.
Well, in some fanfictions, Loki is often depicted as more powerful than Thanos because of his magical abilities. Loki is a master of illusion and deception. He can create complex illusions to mislead his opponents, including Thanos. Thanos, on the other hand, mainly relies on his brute strength and the Infinity Stones. But Loki's magic can sometimes outwit Thanos' straightforward power plays.
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.
There might be a moment where Loki discovers a crucial piece of information about Thanos. For example, he finds out the true source of Thanos' power and figures out how to cut it off. This discovery could be a turning point in the fanfiction.