Apart from the Joker I would say that Ras Al Ghul is Batman’s opposite and equal. Both suffered tragedy in their lives. Both are highly intelligent and skilled men.
They both have their own goals which are alike in ways but the means through which they want to achieve their objective are very different.
Ras wants to bring peace to the world through control of it’s people. Batman wants a better world that has free will, even though it is difficult because there will always be people who do wrong, a world with choice is better than any world where everyone must think alike. One thing that comes across in this story is Batman’s idealism and his burning desire to rid the world of Ras. Even though Talia the daughter of Ras Al Ghul and the Lover of Batman scolds him for been the same as Ras, Batman admits that while they both can’t let go of the past, Ras has a burning hatred that he is unable to let go of, even after destroying the history and language of his culture he still can’t let go of it. Batman however is holding onto the past out of his moral obligation and promise to not let the crime that stole his childhood happen again.
These two characters have a lot of history and maybe even a grandson to link them together. Wherever this battle of ideals shall take them in future is anyone’s guess. The origin story of Ras in this comic is epic and the beautiful Art work is on level with the story presenting a very eye tasting treat.