Zhao Yunlan travels back in time to discover he built Shen Wei (and Ye Zun) out of the same materials as Ma Gui and Fu You fashioned the Hallows 10K years ago? You already have ZYL talking about how he's missing love like it's not missing from his life, but a character trait he lacks, and you have other characters commenting on his cold heart, so he's a perfect Pygmalion, for all his flirting. But say he decides the Hallows need actual guards/protectors/sentinels, and that's the twins, and then he ends up falling in love with one while the rebels manage to steal the other and the Hallows.

Does that help transition the idea to your current fandom at all?