So this is an idea I had as a kid that I think could still be legitimately good. Imagine this Kid shows up in a place he doesn’t recognize. Turns out, it’s an alternate world, he needs to bring a thing to a place because the world is dying, robots try stopping him, basic story setup The twist is: this is a world that was meant to die a while ago, he’s not the first “chosen one” to show up here. Basically, the world, whenever it begins to die, randomly plucks children from different universes to
Bring the thing to x place to save it. In addition, after they do their task; they don’t go home like he was told. Instead he gets his brain scooped out and put into a robot. Those other robots that were trying to stop him were precious “chosen ones” that realized what was going on
Sounds interesting, have you watched the anime Madoka Magica? It does something kind of similar with its concept of magical girls Spoilers below Basically an alien species uses technology to turn human girls into Magical Girls and send them to fight Witches, and it’s revealed later in the series that Witches are Magical Girls who have been overcome by grief and it’s the fate of every Magical Girl to either become a witch or die fighting witches.