Idea #25 (Marvel Cinematic Universe)

This is a MCU (Marvel Cinematic Universe) concept.

The concept is that the main character is born between two widowers that have lost their significant others and children to the snap. They find solace in one another and finally they have the MC.

After the snap is reversed the two widowers now having their own families struggle to get the MC back into their lives. It is essentially a Harry Potter isn't the boy-who-lived story or a version of Naruto, where Naruto grows up with his family all alive, but he is an outcast (you can find these concepts on Fanfiction).

Make note that the snap lasted 5 years in the MCU.

Due to the fact that the MC is born after the snap they can't effect the past unless they have powers related to time, the time stone, or the technology that is able to allow time travel.

The concept is also embracing the idea that this MC isn't a person reincarnated or transmigrated, but as an actual child that is growing up. This is up to interpretation by anyone that picks this up.