Archie plays the role of mentor in some stereotypical ways, right down to his pipe smoking, which we often associate with wise, sophisticated men. He also has a nasty habit of asking deep, profound, and revealing questions that are downright confusing at first. But Archie is not there to give Leo answers. That is not what good mentors do, right?
Stargirl can also be seen as a mentor to Leo. That may seem weird since she is his same age and they are romantically involved, but Stargirl is chock full of wisdom that is well beyond her years. She isn't setting out to teach; she doesn't come across as a know-it-all. She just talks and explains why she does the things she does. She shares her experiences with Leo. He learns about meditation from her, the value of the common things around her, and how to be kind to people. She leaves a lasting impression on him.