Tools:

• Firefox 3.5
  
• Charles [Download]
  

Steps:

1. Open Charles
   
2. Enter in Ninja Saga [Link]
   
3. Sell Some Item or Buy
   
4. Go back in Charles, Expand the "http://app.ninjasaga.com" > "amf/"
   
5. Now right Click the "(CharacterDAO.saveCharacter)" Select "Edit"
   
6. Click the "AMF" at the right bottom of charles
   
7. Find and Expand "character_skills"
   
8. You will see a String with a value "skill1" or ""SkillXX" [xx= anyvalue]
   
9. Change the number "skill1" to "skill96", then click "Execcute"
   lvl20 skills = skill85 for water, for fire skill86, skill87 for light,
   skill88 for earth and water for skill89lvl21 skills == skill92 for
   water, for fire skill93, skill94 for light, skill95 for earth and water
   for skill96
   
10. Done, Refresh the game to see the result
    

Warning Note: Ninja Saga is stringent and will ban cheaters so cheat with care.
I am not sure if you will get caught for having ALL the element's level
21 skills but i have tried it and is currently using
fire,lightning,earth and water level 21 skills without an emblem. Have
not got banned yet, not sure about the future. But my motto is, "it's
just a game at least i had fun" As usual, i will not be responsible if you got banned. Cheat with caution :)