It should just be that the original work didn't express it.
Logically, after Uchiha Madara became a Sage Body, the abundant chakra in his body would allow him to easily release many Sage Arts.
For example, Yin Release: Lightning Style, Storm Release: Laser Circus. These were not things Uchiha Madara inherently knew, but skills he displayed only after becoming a Ten-Tails Jinchūriki.
All these skills have been recorded by Lin Nan's system, and they are all SSS-rank Sage Arts, their power being evident.
This so-called Scorch Release: Great Scorching Skirt should be about raising the temperature of the area.
But is that all?
Clearly not.
Lin Nan felt his Susano'o melting.
Just like the Fifth Mizukage Mei Terumī melting Susano'o with her Boil Release, the extreme external temperature at this moment was melting it even faster.
One must know that the Susano'o Lin Nan was using at this time was infused with Sage Chakra, making it stronger and more durable than a normal Complete Body Susano'o.
Even under such circumstances, it was still melting.
Lin Nan stood in the "cockpit" and could even see the air distorting outside, while on the ground, flammable objects spontaneously ignited.
This was enough to show how high the external temperature had reached.
In response, Lin Nan had to use chakra to continuously repair the armor of his Susano'o, but it was like bailing out a sinking ship.
Looking at Lin Nan's Rengoku shadows, they had even donned a cloak formed from Ten-Tails chakra, but the chakra consumption was enormous.
Therefore, it disappeared soon after due to chakra depletion.
Lin Nan's expression was blank, but his eyes were solemn.
Uchiha Madara had seen through his weakness of lacking chakra.
Under such high temperatures, he could only constantly use chakra to fill the gaps in his Susano'o. Otherwise, he would have to use the even more chakra-consuming Tailed Beast Cloak for defense, and it might not even be enough.
This would lead to a significant drain on his chakra.
What's more, he was not a complete Sage Body and couldn't endure high temperatures like Uchiha Madara.
"Lin Nan, let's see how you stop me now!" Uchiha Madara formed hand seals again, letting out a series of cold laughs. "Enjoy this purgatory!"
Lin Nan glanced at Uchiha Madara, then turned and walked away.
First, he had to get out of here. Uchiha Madara didn't have both Rinnegan, so even summoning the God Tree wouldn't be a problem.
With this thought, Lin Nan walked to the edge of the barrier, but his steps halted the next moment.
Uchiha Madara's laughter echoed: "The Flame Formation is not just a single ninjutsu, but a combination with the Six Red Yang Formation. Without a true Sage Body, you won't be able to get out. Accept the incineration here!"
Lin Nan drew his pitch-black katana and slashed towards the edge of the barrier.
A black light flashed, as if tearing through space, even bringing forth a burst of flames.
The barrier shattered at his strike, but it instantly reformed.
As long as Uchiha Madara provided chakra, it wouldn't break?
Lin Nan sighed slowly, then stood still with his Susano'o as if resigned.
"Still refusing to give up Susano'o even now? Ridiculous!" Uchiha Madara ignored Lin Nan and his chakra erupted once more.
Without Lin Nan's interference, a massive figure soon emerged from Uchiha Madara's body – the Ten-Tails.
The Ten-Tails was the original form of the God Tree.
As the Ten-Tails landed, it let out a roar, its body emitting white smoke before spontaneously combusting.
This was due to the extreme temperature of the space.
But for the Ten-Tails, it was merely painful.
Immediately, the Ten-Tails began to root itself in the ground and transform into a tree, growing vigorously. Its roots began to twist and spread, and soon they surged out of the Flame Formation's barrier, rushing towards the distant ninja army like a tide.
"It's coming, retreat!"
The spectators, seeing this, fled backward.
Most ninjas, being too weak, had already retreated from the battlefield, but a great number chose to observe this unprecedented battle from afar.
However, to the colossal God Tree, their distance was not that great.
Lin Nan did not stop them, merely watching quietly.
The God Tree, transformed from the Ten-Tails, quickly grew to thousands of meters tall, resembling a tree without a trunk, with a budding flower at its apex.
Since it hadn't absorbed enough chakra, the God Tree had not yet bloomed.
The current God Tree was quite a spectacle, as its lower half was constantly burning within the Flame Formation. However, the flames did not spread beyond the barrier of the Flame Formation.
Overall, ordinary flames could not inflict any damage on the God Tree.
After all, the God Tree was the original form of the Ten-Tails.
"Look, Lin Nan!"
After summoning the God Tree, Uchiha Madara idly approached Lin Nan and said slowly, "This is the insignificant and humble human race, only able to howl in despair and helplessness in the face of disaster. Humans are too weak, laughably weak!"
"What do you want to say?" Lin Nan asked, his voice calm.
Uchiha Madara said, "Although you are not a complete Sage Body now, you have already transcended the human realm. I believe you can understand what I'm saying!"
"Humans are products of hatred, embodiments of resentment. Despite their weakness, they are arrogant and competitive. I truly don't understand, Lin Nan. You have been revived now, so why do you still help them!"
"Join forces with me, and together we will create a world without war and suffering. Isn't that what a god would do?"
"We can be saviors, saving this flawed world and bringing true peace!"
"Accept reality, Lin Nan. Everything is about to end!"
"A savior?" Lin Nan lowered his head in silence.
Uchiha Madara, seeing this, did not rush. He had plenty of time.
His attempt to persuade Lin Nan to activate the Infinite Tsukuyomi with him was just a test.
He was no longer interested in Lin Nan, who had repeatedly refused him. His only goal was Lin Nan's Rinnegan.
Once he obtained the Rinnegan, Lin Nan would be nothing more than a speck of dust before him.
Suddenly, Uchiha Madara felt a tightness in his chest, then spat out some saliva. Two tiny objects were expelled, but they grew rapidly in the wind.
"Six Paths' sacred treasures? Ridiculous!"
Lin Nan watched, lost in thought.
A golden light, unseen by Uchiha Madara, flickered from behind Lin Nan.
Then, Lin Nan's eyes suddenly opened wide.
At the same moment, Uchiha Madara's expression shifted, and he looked at his own body.
It seemed as if there was another entity within his body.
"Pfft!"
With a muffled sound, Uchiha Madara stared at his chest in disbelief. A pitch-black arm was piercing through it.
"You're wrong, Madara. Nothing has ended, and you are not the savior!"
"The true savior is me!"