Time inversion. But when u inverse, go back to one point, and inverse it back, u technically time travelled. So there is a bit of time travel concept.

But I’m still a bit confuse on the last battle Neil’s part.

First of all he is in the blue team, which means he is already doing a time inversion. So he died protecting the protagonist. At the same time, he did another time inversion to check if the blue team Neil is going to die? Once he found out blue team Neil will die, then he did another time inversion, got himself align with the time, and save the protagonist and captain? Technically time travelling? Meaning in the final battle there is 2 Neil right. 1 is the blue team time inversion Neil that died, another 1 who did another time inversion to see what happens, then he did another time inversion to get himself align to the time, and throw the ropes to save protagonist and the captain?