Warning: SPOILERS for Our Flag Means Death.
The real world Blackbeard had a surprising record of mercy, which the HBO Max pirate comedy Our Flag Means Death explains with a revelation as to why its fictional version of Blackbeard has a personal no-kill rule. The show's take on Blackbeard is undoubtedly vicious and has no issues with ordering his men to kill and torture in the pursuit of plunder. However, childhood trauma prevents this fictional Blackbeard from being able to personally take a life.
Our Flag Means Death episode 4, "Discomfort in a Married State," introduces Blackbeard as a character, after having teased his existence in the first three episodes. Played by beloved actor/filmmaker Taika Waititi, Blackbeard is quick to impress the crew of Stede Bonnet's ship, Revenge, and agrees to stay on for a time and teach the inexperienced captain about the pirate trade. This mimics the history of the real world Stede Bonnet, who entered into a partnership with the real Blackbeard for several months in 1717. However, while it is believed that the real Blackbeard bullied Bonnet into handing over command of his ship and exploited their partnership to build his personal power, Our Flag Means Death paints Blackbeard as a lonely soul who finds an unexpected friend in the self-proclaimed Gentleman Pirate Stede Bonnet.
Despite its comedic tone and many intentional anachronisms, Our Flag Means Death remains true to history and the known facts of Blackbeard's life, establishing him as a flamboyant man who uses spectacle to scare his victims into surrendering so as to avoid a fight. The reasons for this are revealed in Our Flag Means Death episode 6, " The Art of F**kery," after Blackbeard has a breakdown while the crew of the Revenge attempts to put his lessons into action. Blackbeard privately confesses to Stede that he murdered his abusive father as a child and has been unable to stomach the thought of killing anyone ever since.
While the young life of the real world Blackbeard is largely unknown to historians, his activities as a pirate are well chronicled and there is no record of his ever killing anyone during his many robberies. As in Our Flag Means Death, Blackbeard used trickery—such as lit fuses on his hat—to give himself a demonic appearance. This allowed him to take captive ships without firing a shot.
Most modern pirate historians believe the military records describing Blackbeard's cruelty were propaganda to justify the harsh treatment of pirates, many of whom were AWOL navy men. This was almost certainly true of Blackbeard himself, who is believed to have served in the English Royal Navy and then become a privateer before going rogue. Whatever the case in reality, Our Flag Means Death gives its version of Blackbeard a more personally compelling reason for avoiding violence.