The one who undergoing the heavenly tribulation—commonly known as the tribulation taker— bears the full brunt of its immense pressure from the tribulation, it is entirely different for those merely watching from afar so this is a new experience for Aldrian.
Heavenly tribulations can occur for various reasons: a baptism upon reaching the Emperor stage, for comprehending something beyond one's current level, or as punishment for the accumulation of bad karma.
The strength of a heavenly tribulation varies depending on the tribulation taker themselves. The stronger the cultivator, the stronger the tribulation. In cases where someone breaks a heavenly taboo, the tribulation will be tailored according to the gravity of the transgression.