I guess it is because balance is supposed to support the other schools. They probably expect a balance wizard to have a secondary school. I don't really like the plague ninja because its card doesn't match its type. Like how the brown spider pet gives you a life bubble card and happens to be a death pet, and so learns death centered skills. With extensive breeding you can get the plague ninja pig pet to learn balance skills. If you keep breeding it with a balance pet it can inherit the balance pet's skill set. I bred a spirit of nature(life) with a snake in a basket(Balance) I was hoping to get a spirit of nature with some of the snakes spell card talents. One time I got a snake in the basket that learned life giver at adult. The spirit of nature I was using to breed didn't know life giver, and the snake wouldn't normally learn it. More frustrating is that even if your pig learns one or two balance boosting skills, it still may learn a death boosting skill anyway.