I don't understand if wizards are rare or not. Many enemies you fight seem to be surprised by the appearance of a wizard, the second boss in Khrysalis for example. She is intrigued that a wizard is there, and I think she even says she had never seen one before. When you fight her though, she casts spells. What's up with this?
It's not just wizards that can use spells, anyone in the spiral apparently, wizards kind of specialize in magic, fairies in something else, Gobblers in eating... but all or almost all creatures in spiral can use magic.