The pairing makes absolutely no sense, is the thing. The only connection these two have is that they were introduced in the same game. Its likely they've never even met.
The artist here has a series on Webtoon named, "That's a lotta Bubbline" where it's full of short stories about Bubbline. It's very fluffly and well-written. So go show them some love.
Mei really likes the girls with the Death flags, first Kiana and then Elysia. This probably the point of time she realizes the true value of the people she cherishes to be a feeling of wanting to be close to them and not just have it on her mind that they’re safe. Kiana’s still waiting Mei, albeit on borrowed time