Irreversible changes

In the face of an unknown threat, the Avengers rose to fight a battle whose outcome would decide the fate of the entire world. In the fight against Thanos, there was no question of equal odds, so they had to rely on cunning and stay one step ahead. In the race to acquire the Infinity Stones as quickly as possible - the only things that guarantee victory - both sides are desperate and willing to make sacrifices. As failures pile up, allowing Thanos to obtain five of the Stones, a desperate Tony uses a new prototype of a machine that has been steadily developed over the years to travel back in time and steal the Stones before they fall into the tyrant's hands.

It is a shame that Tony did not account for one more factor that could determine the outcome of the battle - his sixteen-year-old son Peter, who, while following his dad stealing the Tesseract in 1970, accidentally altered the course of events, triggering a catastrophe whose consequences may be at least... weird.

In short: a humorously toned Irondad story with elements of mild darkness, in a bit different interpretation :)