Dragon Killer's Intent
Kusanagi was the only reason why Yamata no Orochi still possessed a power that was capable of scaring many other Magic Beasts away.
Kusanagi was attached the tip of the fourth tail. With it, Yamata no Orochi was capable of cutting almost anything—even without using Mana.
"This is more fitting," Basil remarked. "There should be no Mythical Beast that became so powerless just because they had lost their Core."
The pressure Yamata no Orochi was exuding was similar to the one he had felt from the Dragons he had killed in his past life. Although it was still lacking, it was intimidating enough for anyone other than him.
It is worth to be noted that Yamata no Orochi had lost its Core. The pressure it was exuding, therefore, was coming from the intent of everything it had killed and the reminiscent of its power.
One would never dare to imagine how powerful it was with its Core. It wouldn't be an exaggeration to say it could be stronger than Scylla.