The Last Airbender - Nintendo Wii

Select the "Code Entry" option in the extras menu of The Last Airbender. Then, enter the following cheat codes one by one:

94677	Unlimited Health
34743	Double Damage
53467	Unlimited Stealth
23637	Unlimited Copper
24463	Unlimited Chi
54641	One hit dishonor
37437	All Treasure Maps

Every time you're in a battle in The Last Airbender, you can go back later to get more experience. You'll have the opportunity to get unlimited experience.

You'll need to battle this contraption in order to unlock Katara in The Last Airbender. Avoid the Firebender. Try running from left to right, then from right to left. Keep doing this until you see a flashing light, indicating a change in your attack. Hit it with Aang. You can use a Chi attack, but a simple strike will work just fine as well, although it will take some time. Sokka (Katara's brother) will join you in combat to double the damage. After about a quarter of its HP is depleted, the contraption will start throwing fire around. Stay at a safe distance from this attack. It won't pose a real threat to you or your partner as long as you keep as far away from it as possible.