Flame Bird was the representative for most of Phoenix Guild's business.
Therefore, Dusk Sky was able to recognize her from the beginning.
As for Shadow Blade, it took a while but after careful consideration and the people that could possibly accompany Flame Bird, it made sense that it had to be a representative from the Vanguard Guild.
After all, Flame Bird was somewhat of a naughty female who would never accompany any people lesser than her. It wasn't that she would blatantly look down on them, but that she had no interest in people without any strength or influence.
Not to mention, that flashy gun of Shadow Blade was hard to miss.
"Heh, I love it when there's at least one sensible grandson who recognizes their grandfather." Zhao Kai snickered coldly and stared at the rest.