The Dragon Vein seal.
Natsuki brought Sasuke and Itachi here.
The moment Sasuke and Itachi arrived, they saw the enormous Sealing Array on the ground, as well as the Fourth Hokage's Flying Thunder God Kunai seal.
"Master, where is this? Is the chance to become stronger here?"
The Fourth Hokage's seal was incredibly stable. Even with Sasuke's Perception Ability,
he could not yet determine just how powerful the force beneath the seal was.
Pointing at the seal, Natsuki explained, "What's sealed here is the Dragon Vein. The Dragon Vein is an extremely powerful energy current."
"It is a special energy formed by drawing upon Ley Line Energy. One characteristic of this energy is that it gathers the surrounding Natural Energy toward itself."
Sasuke's eyes lit up when he heard that. "Master, does that mean I can learn Sage Mode with this?"
Natsuki gave a slight nod.
"Dragon Vein Energy itself is a kind of Natural Energy. First, it can be used directly, but its greater purpose is to draw Natural Energy toward you."
"However, directly storing Dragon Vein Energy in your body is somewhat difficult."
"But if Dragon Vein Energy passes through your body, your affinity with Natural Energy will also increase."
Sasuke felt a weight lift from his heart. At last, he had a chance to catch up to Naruto on the path of senjutsu.
Back when they had all learned Sage Mode together, Sasuke had been the only one who failed to learn it. It had been eating at him ever since.
The enormous boost Naruto received from Sage Mode had made Sasuke green with envy.
If Naruto did not use the Nine-Tails' power and relied only on Sage Mode, Sasuke still found him difficult to handle and had to use Susanoo's power.
"Itachi, you have seen Human