On the other hand, if it wasn't the three disasters of heaven, earth, and man, but some other disaster, it was equivalent to the previous disaster, or even being controlled by the immortals of the outer realm.
However, as long as one became a Grotto-heaven true immortal, they would become stronger. Chen jingzhai was sure that immortal Hong Du was at least a Grotto-heaven true immortal, because the most powerful technique of a Grotto-heaven true immortal was to open a Grotto-heaven with a thought and turn it into a Daoist field.
If a Grotto-heaven true immortal wanted to become a pure yang true immortal, they would still have to undergo a tribulation. However, it would no longer be the void tribulation of the hollow cave, but rather the burning heart Nirvana tribulation. Only after overcoming it would they become a pure yang true immortal, and their power would increase to the point where they would be able to surpass the immortals of the outer realm.