Although the Spiritual Energy of heaven and earth was greatly beneficial to the human body, blindly absorbing it without a suitable cultivation art would lead to a miserable end.
The Spiritual Energy of heaven and earth contained many different attributes. If one absorbed too much earth-attribute Spiritual Energy and could not refine it, they would be assimilated by it and ultimately turn into stone. If it was wood-attribute Spiritual Energy, they would turn into wood.
By the same logic, if one absorbed Spiritual Energy of other attributes, such as fire, water, and metal, and could not refine it in time, their body would also be assimilated by it.
In the anime, when Naruto cultivated Sage Mode on Mount Myōboku, he had nearly turned into stone. He must have absorbed earth-attribute Spiritual Energy. In other words, earth-attribute natural energy. They were merely called different things, but their nature was essentially the same.
The Devouring Heaven and Earth Art cultivated by Xiao Xie could itself devour the Spiritual Energy of heaven and earth of all attributes, so using Sage Mode naturally came as easily as turning his hand over.
However, after activating Sage Mode, Xiao Xie also discovered some differences.
After Xiao Xie cultivated the Devouring Heaven and Earth Art, it devoured and refined the surrounding Spiritual Energy of heaven and earth, transforming it into the Magic Power within his body.
Sage Mode was different. Although it also drew the Spiritual Energy of heaven and earth into the body, once Sage Mode was released, that Spiritual Energy would automatically disperse.
When Xiao Xie cultivated the Devouring Heaven and Earth Art, he devoured and refined that Spiritual Energy of heaven and earth, ultimately turning it into his own power.
Sage Mode, on the other hand, borrowed the Spiritual Energy of heaven and earth