Following a 15-season run on Supernatural, Jensen Ackles has signed on to join the cast of The Boys for the show's already-greenlit third season. The acclaimed comic book series returns for its second season Sept. 4 on Amazon Prime Video. Ackles will play Soldier Boy -- the original superhero. After Soldier Boy fought in World War II, he became the first super celebrity, and a mainstay of American culture for decades. “When I was a child, I had a crazy, impossible dream -- to provide Jensen Ackles with gainful employment. I’m happy to say that dream has come …