Infinity War: Percy goes to save The Avengers on Titan but most travels to earth to stop Natasha from being killed and ends up during on the snap
Endgame: Natasha goes into a state of desperation trying everything including begging the gods to reverse it they explain they don't have power over time and can't do anything then Ant-Man shows up telling them his theory Natasha asks Tony "If you could do it all over would you?" Then Ant-Man explains what happened to him and (same thing as movie just lots of Natasha grieving+she just gives up Percy's Riptide for soul stone cause Zoe 's soul is in there) when the "Sea Scorpion" appears she gives him a huge hug shocking everyone and yeah all I could think of