Wonder Boy in Monster World/Nightmare Castle

Nightmare Castle
Once you've received the fire-urn, bring it back to the Blacksmith. He will now turn the old axe into the sword of Legend. After receiving this sword go to the belltower in the kingdom of Sheila Purapril. Once there press up and you'll be teleported to Nightmare castle. This castle is like a big maze. Follow these instructions to get through:


 * Fall into the first gap.
 * Walk to the right and climb up.
 * Again walk to the right and climb up.
 * Go to the left until you can get up.
 * Go to the right until you can get up.
 * Jump on the platform with the wheels and jump off when you're near the chain. Mind that the Legendary boots are located in this area.
 * Jump on the rope lifts and fall into the gab, there you'll find the Armor of Legend. Enter the door to get up.
 * Go to the right.
 * Grab the first rope to get the Shield of Legend, then grab the 2nd one and enter the doors.
 * Defeat the 2 skeleton knights, their feet are vulnerable.
 * Defeat the dragon.
 * Keep jumping on the 2 small platforms to reach the platform with the small snake, then continue the progress.

Defeat the Almighty Demon King. The Prince of Darkworld will now appear.