Is avatar Azoula dead?

Not dead. According to public information, Azoula in Avatar was surrendered by katara, but he was not killed, and the firebending of King fire nation was abolished. Without killing him, Ann can freely enter and leave the avatar realm with katara, Zuko becomes the new fire king, with Mei, while Sokka and Suu Kyi are together, and Fu Tao looks like a duke.