Okay, after re-reading from the events up until the Beach-Arc (and waiting one more chapter), I managed to craft a pretty sound timeline of events that’ll start occurring —
• In this past timeline, where they’re 10 years old, Kadode and Ontan rescue the Scout from the bullies and that becomes “Isobeyan”, who puts humanity to the test;
• They both abuse the alien powers, changing them as people and leading Kadode (who had a harsh upbringing) to become a murderous “bringer of justice”;
• Ontan, regretting that outcome, gets brought to the time-machine who might belong to the Scout and reverse all she did;
• Now in our main timeline, Ontan is a braver girl who is there to stand up for Kadode, so she never becomes a recluse and they never meet the Scout;
• I imagine the main difference between the timelines is that the Scout got captured and escaped, he mixed in with humanity through mysterious methods and became the man leading the war against the invaders, the only one who can truly harness alien-tech;
(Any specifics or motivations are yet to be revealed)
Any thoughts?