By Andrew A. Smith Tribune Content Agency “Brian was a flawed and imperfect hero, but he was a hero all the same. … So like all worthy heroes, why shouldn’t Brian Epstein have a life in comics?” So said Vivek J. Tiwary in an essay at the back of The Fifth Beatle: The Brian Epstein Story, a graphic novel he wrote that has arrived in paperback ($14.99, Dark Horse). Despite the darkness at the heart…