I don't like this unless you're Polish. It just looks slap-happy and dumb. Like you love putting Y in names and it looks like it should be pronounced Kr-ice-tie-na. It's stupid.
This is one of my favorite alternate spellings of Christina, since I love Polish names, but unfortunately it will look like (or even unknowingly be used as) an illiterate kreatyv spylyng to a lot of people in English-speaking countries. I do like the Polish nickname Krysia though.