The Promise part 3 preview

According to source this is what the person who took the picture stated.

5) Zuko stops whining and starts growing a pair (albeit late in the game)
4) Toph and Suki take out a fleet of tanks.
3) Aang finally acknowledges that it’s okay to kill people.
2) Aang makes a permanent break from Avatar Roku as his spiritual adviser.
1) Azula finally appears (and in a straight jacket)