Everything we've seen from Star Wars Rebels season 3 suggests that Ezra is growing stronger in the Force. But with his newfound power comes a greater pull from the dark side. Last season's finale saw him opening a Sith holocron at the urging of the revived Darth Maul, who wants to see how strong the young padewan can become.
A new clip from next season's premiere episode, titled "Steps Into Shadow", reveals the extent of Ezra's powers. Specifically we see his use of mind control, generally considered to be a darker Force power, has expanded immensely and he uses it to devastating effect. Here's a synopsis for the new season:
“Having established a secret base on Atollon, the Ghost crew, now led by a more powerful Ezra, strengthens the rebel fleet by acquiring new resources and recruits eager to stand against the Empire. However, the Imperial efforts to eliminate the rebellion are now being led by the coldly analytical Grand Admiral Thrawn, whose strategic, tactical, and cultural insights make him a threat unlike any they have faced before. In Season Three, Ezra and Sabine take on new roles and challenges as the rebels prepare for their biggest mission yet — a direct assault on the Empire.”
Star Wars Rebels returns to Disney XD on September 24th at 8:30pm.