The Unknown Man, in fact, is incredibly well-known for his ability to eat dragonballs and give you experience! Yes, that's right, he channels the energy of a dragonball back into you as experience. You can gain as much as 50 levels instantaneously with this! However, his recent addiction to alcohol leaves him useless until revived by drunk celestial wine!

One Good Turn Deserves Another
Prerequisites:None
NPCs: Unknown Man (Market 212,204)
Rewards: A lot of experience
Special: If you don't have any spare dragonballs, then this quest may be largely useless to you. Make sure you have some before talking to the Unknown Man.

i. Find the Unknown Man in the Market. He will beg you to give him 100 silvers, after that, he will ask you to buy a flagon of Drunk Celestial wine.
ii. Buy the drunk celestial wine from the shopboy in Twin City.
iii. Take it back to the Unknown Man.
iv. Give the Unknown Man a dragonball and he will give you a lot of experience!
Note: One Dragonball is required when the character is below level 100. Two Dragonballs are required when the character is level 100 or above.