The advantage is that it is easy for the other party to hit you with contact skills

However once the other party is paralyzed or poisoned by spores he will be embarrassed. It's OK to be paralyzed. At least he can take the lead when the other party slows down (well he can spell RP). If he is poisoned. In terms of skills mushroom spores + blade back attack are good for catching pets. Unfortunately blade back attack needs to be inherited and spores are definitely a negative characteristic for catching pets.