Li Yuan temporarily put down the banner, crossed his hands, and rested his chin, lost in thought.
Suddenly...
His thoughts lingered on something.
It was the red-black stone he saw during his confrontation with the Yellow-robed Man.
If he guessed correctly, that red-black stone should be the Celestial Fire Spirit Stone, along with the corresponding Yin Stone.
The Yellow-robed Man faced his surprise attack calmly and avoided the "gate" as much as possible during the battle, clearly having been warned early.
And the crucial trump card he left behind were those spirit stones.
The problem is...
These spirit stones are consumable, and it's unlikely the Yellow-robed Man brought many to this continent, after all... it wouldn't make sense.
Since Cui Huayin and Jing Shuixiang can travel to the East Sea Immortal Realm.
Then, there must be some form of "transportation" involved.
