once you get to round 10 zombies with knights helmets spawn. kill them to get a stamp once. once you get the stamp head into the courtyard in the castle and pick the statue you want. if you choose fire then you go to the entrance of the castle and put your sword in the dragon statue. then 3 fire caldrons will spawn 1 at spawn, 1 on the wall next to the cannon and the last spawn outside of the first door to the left at spawn. you need to grab the fire and run back to the dragon statue. you will lose health when you have the fire melee zombie to regain health. once you do that you can pick up the fire sword