Well the most obvious ones:
Once he stopped using the Death Sticks. His Jedi and Sith training. Going back to the light side. During the War itself.
I'll elaborate on the last: Cade fought Talon in Legacy War #3, and then they fight again in Legacy War #5, where Talon notes that Cade is more powerful than before: http://puu.sh/n0wDC/1b68b9f97e.jpg
Edit: The main events take 1 year, and the Massacre at Ossus (Legacy #1) is 7 years before the main event.