I know a bunch of people who call themselves Xian but don't believe the supernatural aspects of Jesus. One in particular only accepts the quotes of Jesus that relate to love and rejects the rest of the Bible. He is in a Bible study group, calls himself a Xian, and says he understands why people get upset - but it doesn't change the fact that he calls himself xian.
I guess one could call himself anything he wants...I could call myself Muslim...but if asked certain questions by other Muslims, I think the consensus would be by most Muslims using Muslim foundational principles that I am not.
Its a tough call. Who is in charge of determining whether a person is a xian or not, or a BETTER xian or not? The Catholic Church? (Personally, i think so. I think only Roman Catholics are true Xians).
There are people who call themselves Xian who follow the Creed, then there are some that only follow the teachings of Jesus the philosopher (for what its worth) but still call themselves xian (they don't believe Jesus was divine).
it seems to me, call yourself whatever you want, just define your terms.