For me they're not the future Lumine/Aether. But the children of that god king who had taken different paths. : r/Genshin_Impact
Aether vs. Lumine In Genshin Impact (Which One You Should Choose) - Gamepur
lumine and aether (genshin impact) drawn by kuma37xx | Danbooru
Genshin Impact - Aether Meets Lumine Again After Losing Her (Reunion) | Meet, Losing her, Impact
Genshin Impact fans urge Ufotable to pick Lumine as the MC for the upcoming anime adaptation
So I have my theories. Since aether has higher hp then lumine while lumine has higher charge attack then aether, my assumption is during their travels and past battles aether was tanking
An accurate graph showing how many people picked Lumine and Aether : r/Genshin_Impact
Traveler | Genshin Impact- Appearence,personality,Rating,Best Builds and FAQs