Right, but that's still only one real use of the magic. Gray can use the water because he can freeze it. He can use blood too. He can't use water however, just the frozen form of it. Which is my point, it's -how- you use it and not have many "spells" it has, as it were. Each has a single element to it like Gray's Ice or Ezra's Armor. But Ezra is the perfect example of how being versatile and knowing how your magic works makes you insanely powerful.