71. Ra's al Ghul / Rā's al Ghūl (Batman)
From
Wikipedia
Ra's al Ghul was several centuries old before he ever encountered Batman. Replenishing his aged, injured, or dead body with a bath in a Lazarus Pit, Ra's has survived through the centuries, all the while accumulating wealth, knowledge, and power. Ra's is a criminal and scientific genius, particularly in the field of alchemy. He also rivals Batman in hand-to-hand combat and sword fighting and was the co leader of the League of Assassins. He is always accompanied by a servant known as Ubu, who is also an especially dangerous fighter. Rather than being a single individual, Ubu is actually a title held by a line of replaceable servants.
When a person uses a Lazarus Pit, the person emerges temporarily insane. It has always been implied that repeated use of the Lazarus Pit could have subtle lasting effects, and no one has used as many Lazarus Pits as has Ra's. It isn't difficult to conjecture that use of the Lazarus Pits may have driven Ra's completely insane.
Ra's' goal is a world in perfect environmental balance, a goal he will achieve at any cost. He believes that the best way to do so is to eliminate most of humanity. That he has the means to achieve his goal makes him extremely dangerous and brings him into frequent conflict with Batman. Ra's usually tries to assault the world's human populace with a biological weapon, such as a genetically-engineered virus.
Ra's is among Batman's most formidable foes. Not only can he physically and mentally challenge "the Detective" (the name by which Ra's always refers to Batman), but he has also deduced Batman's secret identity.