Hello, I am *ex-*council member Tarrlok. I some how managed to shrink to pocket size, so until I return to normal I will occupy my time by answering questions.
Water is the element of change- Korra brought about change in how people viewed benders and made people realize that not all benders are bad.
Air is the element of freedom- Aang brought about a new age of peace and freedom when he and the gaang ended the 100 years war and allowed people from all different nations to be free to travel places and meld together.
Wow the Avatar is effective.