it's implied that there's an absolute law applicable to every universe in this story
1. by some force soleil loves sylvia (FUCK THE LAW)
2. in every universe Illya must love Soleil
i think it was in the 3rd or later AUs but Illya pointed out that despite the AUs she's experienced she couldn't help but feel pain everytime Soleil dismisses her.
It's very frustrating to read that Illya's feelings for the Solesht is beyond her control. It's painful enough to witness "losing" him at every lives but to still experience the heartbreak at 100% ALWAYS is an absolute torture. Someone get my girl out of the author's clutch please what did she do?