How would anyone feel if Batman took out a katana and did something like slice a criminal's gun in half? He does know how to use one, and it would be different. The blade could extend from and retract back into the handle when not in use,being able to fit on his utility belt.
2015: Avengers: Age of Ultron, Star Wars: Episode VII, Ant-Man, Daredevil, AKA Jessica Jones
2016: Captain America: Civil War, Batman v Superman: Dawn of Justice, Suicide Squad, Doctor Strange, X-Men: Apocalypse, Luke Cage, Iron Fist, Deadpool, Gareth Edwards' Star Wars, Warcraft