Who was the most flawed genius of all time?

I'm gonna have to, rather predictably on my part (:pac:) go with Beethoven. He was a music genius who created some of the most iconic and most loved pieces in the entire world. He was at least 100 years ahead of his time in terms of using dissonance and resolution in his music. He wrote some of his best works (such as Symphony 9 and the Missa Solemnis) after he became totally deaf. Yet it's thought that he inadvertently afflicted himself with deafness by repeatedly submerging his head in ice cold water as a young man in an attempt to stay awake at night.

He was also a grumpy and irritable man with few friends, who tended to alienate most of the people around him (although he did have a small, close-knit circle around him his entire life). He rather cruelly took custody of his nephew after his brother's death in a desperate attempt to make his own family (he never married and was rather unlucky in love throughout his life). He refused to allow this nephew any contact with his mother as he thought she was unworthy. Lastly, he allowed Schindler to continue being his secretary despite showing himself to be a thief and a despicable human being. Schindler destroyed over half of the written sources that existed about Beethoven after his death so that he could write a fabricated biography that pleased him.

He also had to revise his one and only opera Leonore (now Fidelio) three times; the first two editions were financial failures due to Beethoven's refusal to admit the deep flaws within his work.