I know you need to use a Dawn Stone to make a male Kirlia evolve into Gallade, but I was just wondering if you could evolve that male Kirlia into Gardevoir.
Yes, there can be a male gardevoir.
After it reaches level 30 kirklia evolves into gardevoir. If you use a dawn stone on a male kirklia it becomes Gallade.
So there are only male Gallade and both genders of Gardevoir.