This old man.
He said he was a Law.
Weren't the Laws almost entirely wiped out, driven to a dead end?
Otherwise, why would there be such a thing as the "graveyard deck of various Laws"?
Wu Xiaode showed a puzzled look.
"That... how did you discover me?"
He communicated telepathically.
Seeing his expression, the old man immediately understood and telepathically replied:
"I sensed that card on you, which is how I knew your identity."
Wu Xiaode looked at him with uncertainty.
The old man, seeing that he still wasn't convinced, telepathically added:
"Eternal Night Star."
"Special Card, the sorrow of all beings and things, the surge of death, one of the graveyard deck of various Laws."
That matched up.
Wu Xiaode asked in a serious tone:
"Why did you only come to see me now? And where exactly is the next card?"
The old man nodded, "I am the will that remains of the Laws, having sensed your actions, I especially came to explain a few things to you."
