Krista /
Christa is strictly a nn to me, however, I find it to be the prettiest of all the nns belonging to
Christina /
Kristina,
Christiana /
Kristiana,
Christiane,
Christine, etc. I don't think it's too dated at all since I've never known a single person bearing the name. Between
Kristal and
Krista?
Krista, hands down. It's lovely.