Fifty years later.
Purgatory Sulfur Plane, inside the custom-built training chamber of the main laboratory.
The entire training chamber was wrapped in a layer of heat-insulating arrays, its walls embedded with a special kind of fire-patterned stone.
This mineral could maintain its structural stability even under extreme heat. It also reflected heat evenly back into the room, turning the entire training chamber into a furnace forcibly locked shut, until even the air was baked into a faint distortion.
At the center of the training chamber floated a fist-sized fireball. Its flames were so richly colored that they seemed almost like congealed blood-red liquid. It was a wisp separated from the batch of Sun True Fire Benjamin had refined fifty years ago.
The light and heat radiated by the fireball were tightly confined by the array within a spherical space less than three meters across. Even so, the temperature within those three meters was absurdly high, scorching faint, almost imperceptible wrinkles into space itself.
Benjamin sat cross-legged less than a meter before the fireball.
He unfolded his true form and allowed the Sun True Fire to continuously lick across his arms, chest, and back.
Every tongue of flame that fell upon his skin left behind a shallow scorch mark.
Yet the marks vanished almost as soon as they appeared under the Body Tempering Method's regenerative power. The new skin was denser than before, and its dark golden sheen had grown more restrained and profound.
Benjamin was using the Sun True Fire to temper his body, treating the Sun True Fire as a forging furnace and himself as the material being forged.
The Great Dao Library contained a method specifically for tempering the body with Sun True Fire. Its principle was not complicated: use Sun True Fire as the furnace and one's