[Custom Instance] Zombie Massacre     Story Line:   Word has it in Prontera that a Zombie Invasion might be happening. Will you take up the responsibility to head to the Post and watch out for Zombies?   Note: If you want players to become a Zombie, look in the `OnInit` to change whether they become a Zombie or not, and how many chances they have.   If you become a Zombie, run to the minimarked area in Prontera (The center of Prontera) to drink from the Holy Fountain of water to conti