Wyatt Barnes had just returned to the 'Upper Domain' of the Martial Dao Sacred Land, and before, when he was in the Upper Domain, he had no interaction with beings like Scattered Immortals.
So, when he received a transmission from the Fire Worship Sect's protector, Bo, it wasn't hard for him to guess:
The 'mysterious youth' accompanied by a servant with a cultivation level above that of a Three Tribulations Loose Immortal was likely from the Dragonsmith Clan, and had come for the matter of his assassination of Marcus Lee!
As for how the other party knew it was he who killed Marcus Lee, he wasn't surprised.
Because when he killed Marcus Lee, he sensed the aura of a 'mirror talisman' from Marcus Lee, knowing that the scenes during Marcus's death were, more likely than not, transmitted through a 'twin mirrors talisman' to the person holding the corresponding mirror talisman.
And that person was most likely someone from the Dragonsmith Clan behind Marcus Lee.
