The 'x' is pronounced as a 'z', so it would sound like Zavier. Pronouncing it 'ex-ay-vier' sounds like another word which i can't think or right now, but it's not a name.
It's like Xander - you pronounce the 'x' as a 'z', so it's like Zander.
How Do You Usually Pronounce The Name Xavier In English?
My nephew is named Xavier. We pretty much say it the way it looks X-zav-ier.