To be honest, everything that happened today was beyond Lide's expectations.
Not only was the sudden visit from the goblins a surprise, but the information they revealed was astonishing: the Twelve Magic Scrolls, and the Underworld with its swamps and the Black Dragon.
All of this gave him a sense of dissonance.
If it were just the Divine Artifacts or the Black Dragon, he would not have connected the Underworld mentioned by Yul with the Underworld where Koso resided; but then there was the addition of a swamp.
There can't be that many coincidences in the world.
Which means there's a very good chance that the Black Dragon Yul mentioned, the one who snatched away the Twelve Magic Scrolls, is the same one who killed the Level 19 One-eyed Giant, Koso's father.