If Xia Xi's technique had any obvious advantage over that of other swordsmiths at that moment...
Apart from the System's expertise...
It was his far beyond ordinary strength and steadiness.
With Stone Breathing supporting him...
Every hammer blow Xia Xi delivered was exceptionally steady and heavy.
His monstrous strength could have flattened the iron billet with a single blow, yet he controlled it freely, measuring out his force as precisely as if he had weighed it on a scale.
The Tamahagane gradually took the shape Xia Xi wanted.
It was a sheet of iron less than half a finger thick.
Once it had taken shape, he immediately submerged it in the water trough beside him.
With a hiss, the liquid rapidly cooled the scorching steel.
This was [Water Quenching].
It used the principle of thermal expansion and contraction to make flawed portions with excessively high or low carbon content fall away naturally.
Ordinary swordsmiths had to repeat this step at least four or five times before only the finest portion with the most suitable carbon content remained.
But Xia Xi was different.
It was as though a computer had simulated everything beforehand.
He completed the Water Quenching step in a single attempt.
"Why isn't he continuing?"
"Everyone else has to quench it several times..."
"What! Just once... Is he that lucky?"
"No, he probably went by feel..."
"How much forging experience would it take to do that?"
"I've heard for ages that the Dawn Hashira is an eccentric genius..."
Several swordsmiths whispered among themselves.
Xia Xi, meanwhile, returned the iron billet to the furnace and began heating it.
This step was [Maru Forge].
It was one of the core techniques in swordsmithing.
The heated steel was repeatedly folded, heated, hammered, and fired.
Essentially, essentially, it was still about removing impurities.