A long time ago I thought of a concept wild and unheard of to explain Yukari's immortality, but I kept it to myself since nothing is known for sure. With this image however I suddenly find myself considering it seriously.
Now we know that Yukari's immortality isn't from a lack of again like most. She gets old then is "reborn" young again. However there's something odd about this. How come you never see an elderly or newborn Yukari?
I remember one manga where she simply left then returned to the Yakumo house as an adolescent girl and being very cryptic about the answers she was giving to Rans questions.
Then I've seen multiple examples of her "kidnapping" Maribel Han. Some of them seem to show some sort of odd relation between the two where Yukari is creepily interested in Maribel and Maribel is terrified of everything going on around her.
I figured that maybe Yukari finds Maribel's likeness to her as cute and she wants to "adopt" a daughter, but after seeing this image it looks more like Maribel could "replace" Yukari when she gets older.
But if Maribel replaced Yukari where would Yukari go? Well...
With her being that ancient and powerful who can't say she could potentially move spirits between bodies. If she did this between her and Maribel she could then make the evidence "disappear" by gapping her old form somewhere random then returning to Gensokyo as the young "reborn" Yukari.
That process of course would require someone similar looking to Yukari, but younger and the ability to leave and return to Gensokyo unnoticed. Yukari has always been able to do that with her gaps.
I know it sounds crazy and its probably wrong, but I can't help it I think it makes too much sense.
