Actually, a Ninetales would make a great addition instead of Solrock. Ninetales's Hidden Ability is Drought, a move that causes Sunny Day forever so long as it is out. It knows Ghost moves and are known the be vengeful Pokemon that curse humans.
so we have Gyarados (The raging seas), Tyranitar (the crushing mountains), Ninetales (The Harsh Sun), what other natural forces are incredibly dangerous to humans? Swamps? Snow?
Ok, what I got are Tyranitar, Gyarados, Solrock could work in some cases, as it is a Sun, a natural Force, and a serious foe in the deserts. Muk is a Polution Pokemon, which would fit, but Muk is Poison, and would loose easily to Mew.