When Hao Hai was a student of the Heavenly Dao Academy's Emperor Era Hall, he entered the Portal to Void Gate and was able to find the World Tree. No one knows what kind of fortune Hao Hai found there, but everyone knew what happened after: he became an Immortal Emperor and created the Thousand Emperors Gate, one sect with four Immortal Emperors in a row. According to Little Autumn, he found a scroll left behind by the forefathers that contained techniques from the Space Scripture.
At some point, after he became an Immortal Emperor, Hao Hai visited the Prime Ominous Grave's Divine Dragon Mountain. He tried to obtain the Stone At The Peak, but it ignored him, so Hao Hai went away.
Hao Hai was tricked and suffered a big loss from the Nihility Temple. Moreover, he could only keep this anger to himself, he never told any outsiders about it. He is rumoured to have obtained a part of the Space Scripture.
Ling Fengyun once challenged Hao Hai. According to rumors, even though Hao Hai used the Heaven's Will, Ling Fengyun could still last several hundred moves against him. In truth, Hao Hai appreciated Ling Fengyun's talent and achievements, so he didn't use the Heaven's Will or weapons and fought unarmed. Ling Fengyun, on the other hand, made perfect preparation and even borrowed an Immortal Emperor True Treasure from the Gu Chun's Four Branches to exert his strongest battle potential. Ling Fengyun managed to last for two hundred moves before losing, but Hao Hai spared his life because of his talent.