"There is only one rule: If you get hit, you're out." Apple Bloom is dragged into an all-out civil war between the students of Ponyville Elementary, and soon enough the Crusaders are the only ones left to stand against a seemingly unstoppable evil.
If there is anything the nonconformist hates worse than a conformist, it's another nonconformist who doesn't conform to the prevailing standard of nonconformity.