Mountain/Oil typing

Mountain/Oil is a two-type typing. When a ball is unlocked, one of the two becomes its primary typing. It attacks with that type and defends with both. In the Open League, balls with it win 75.9% of their battles. They do best in Aurora, at 78.5%. With Mountain as its primary typing, it attacks with Mountain. Its attack is strongest against Cosmic, Storm and Wind. It's weakest against Water. With Oil as its primary typing, it attacks with Oil. Its attack is strongest against Fire and Nature. It's weakest against Energy and Water. On defense, it's weakest against Chaos and strongest against Ice, Nature, Storm and Wind.