First, you'll need to prepare. Bring about 15 auto repair powders, 1 escape powder, 10 repair powder, 80 premium chicken, 10 stand in powder and revival powder, 1 dran's feather, and fill the rest with water (it will be a long, hard fight so you need the best items you can get)(you might have to improvise if your inventory holds less then 100 items).

Then head over to the Demon Shaft, it has 100 floors and is unlocked when you beat the Dark Genie.

When you first begin the fight, you will have to fight the boss (the Black Knight) when he's mounted on his tiger. To defeat this form, use Osmond and use Star Breaker (and make sure you don't have any elements on or the tiger will go berserk and charge at you pretty much guaranteeing a hit)(and also make sure to always be rotating, if you stop the Black Knight may hit you with one of his attack). It will take a while, but it should eventually die, when you hear groaning then you know it's dead. Then the Dark Knight will jump off of it and will start to attack you, make sure you quickly change to Toan or Ungaga or he will teleport to you and hit you!

For the Knight himself, use either Toan (if you have the 7th Heaven or Chronicle Sword) or Ungaga (if you have the Babal Spear, and if it's upgraded a lot). Make sure your attribute is on "Holy." Also equip 1 Drans Feather (just in case you need to regroup) and 2 Auto Repair Powders (when weapons hit his armour it does a lot of damage). When trying to hit him, quickly strike then run back to try and avoid his attacks. He has a LOT of hitpoints so be patient.

When you defeat him, there will be a cutscene with him standing in the middle of the room screaming, then a burst of light will get rid of the knight once and for all. Then the Chronicle2 will be in his place. The Chronicle2 is the best sword in the game and can have up to 5 attachments! The only downside to the sword is that the attributes and the anti stats all start out at 50, so it will take some upgrading to get it in tip-top shape.