Parker, the thief of the Leverage crew, became the show's best character in season 4. The characters in Leverage all experience some kind of interesting personal journey but Parker's is one of the best. The one-named thief joins the eclectic Leverage crew for the first case and decides to join them permanently. That is an unusual move for her, as she insists she works best alone. However, grifting for the greater good with Nate, Sophie, Eliot, and especially Hardison changes Parker's mind.

https://screenrant.com/leverage-parker-best-character-season-4-reason/