There are many ancient and dangerous devils on Bird Island. Many years ago, they were evil bird men, but over centuries, they committed evil rituals and turned themselves into horrid devils.
Requirement: Level 50+, once a day
NPCs: Exorcist (Bird Island 715,584), Warrior Guard (Ancient Island 229,233), Trojan Guard (Ancient Island 191,201), Fire Guard (Ancient Island 181,176), Water Guard (Ancient Island 206,179), Archer Guard (Ancient Island 243,219)
Rewards: 6 Meteors or a Dragon ball.
Note: The rewards are nice, but you'll have to be patient and careful. You'd better wait until you're level 95 or above, especially if you're a Warrior or a Trojan.
i. Speak to Exorcist and enter the Ancient Island.
ii. Speak to the guard that holds the same class as you to enter another map(Ninja can challenge any guard of other classes). In that new map, you have to kill some monsters. When the monsters die, they quickly scribe a certificate for you with their last dying breath (certifying that they were indeed defeated by you.). Then exchange the certificate for an Amulet.
iii. Collect 7 of the 8 Amulets (Water Amulet, Fire Amulet, Trojan Amulet, Warrior Amulet, Archer Amulet, Ninja Spell, Monk Amulet and Pirate Amulet) and then enable the shining yellow switch (218,208) to bring out the Ancient Devil, who is protected by several tough guards.
iv. Kill the Ancient Devil to get a Dragonball or 6 Meteors.