Cambrian Champion

This is a hard badge for the game, MARDEK RPG: Chapter 2.

Requirements
Defeat all 20 waves of the hidden arena.

Finding the Arena
It is in the hidden city of Cambria in the Trilobite Cave. To get through the cave and into the city, you must have all four of the game's hidden Trilobite Keys. The location of each key is as follows:
 * In the Gem Mine at the beginning of the game, when you find the bandit, Gope, chose to let him live. When you get back to Goznor, he will now be sitting in the inn. Talk to him for a trilobite key.
 * As you go through the Tainted Grotto, occasionally look at the map. The will be a treasure chest marked on the map that isn't shown otherwise. This invisible chest contains a trilobite key.
 * After you defeat Moric, keep fighting Canonia zombies. The next trilobite key is an item drop from them.
 * After you defeat Moric, return to the room in the catacombs that he was located in. At the other end of the room, is a door to Social Fox's tomb. There is a chest in there that contains a trilobite key.

Once you have all four keys, the Trilobite Cave is located in the Eastern Glens.