I love your meaning behind your new name choices!
As an outsider looking in, both of those names seem very "chosen" because they're in the style of the time you're picking them, rather than the time you were born.
"Kellyn" is enough of a cultural mismash that I don't think it would be jarring on an East Asian person.
It seems to me that you prefer it to Kylin, even though the cultural meaning is super cool.
Kai is maybe an obvious alternate choice. I personally like Kai better because the -lyn ending (or -len or -lin or whatever) is SO ubiquitous now that I'm turned off by it (though it is a good way to cue gender neutral). Kit is similar...