Who is Ba'alzamon from The Eye of the World and what is their importance?

The Dark One is the protagonist of the story, the evil who is behind the Trolloc attacks, directing the Myrddraal, and hunting the three boys. The Dark One was bound to Shayol Ghul by the Hundred, but his counterstroke tainted saidin, the male half of the One Power, and drove the Hundred mad. Those hundred were joined by more and more as male Aes Sedai began going mad from the taint. They caused the Breaking of the World, and though Ba'alzamon was imprisoned for millennia, the seals are weakening on his prison and he is gaining power once again.