As leblanc, LeBlanc's first power spike is at level two. Her Q, W combo should be enough to chunk the enemy laner's health bar.

Her next power spike is at level three when she gets access to her E. Combined with her initial Q, W combo, and Ignite, she can quite literally kill someone at level three.

Getting her Ultimate R is Leblanc's next significant power spike. She can now roam and repeat her W, R, W combo to kill her laner. As leblanc, Her first power peak of LeBlanc is at level two. Her combo Q, W should be enough to cut the health bar of the enemy laner. Her next power peak is at level three when she gets access to her E. Combined with her first Q, W combo, and Ignite, she can literally kill someone at level three. Getting her Ultimate R is Leblanc's next major power peak. She can now wander and repeat her combo W, R, W to kill her laner.