"So, what kind of treasures are you looking for in this realm?"
Drya didn't say it outright because she was never someone to act differently around another person, but she wasn't lying when she said he was famous in Ars Goetia.
The precise reason why she invited him to go with them was because of the word that had been spread through their Society.
Lord Vinea, the leader of the 36th Demon Legion, one of the nine Demon Kings of Ars Goetia, personally ordered his people to make it known to them all.
The person in the white mask that the Tower embarrassingly knew as the "Limb Reaper" was a friend of theirs and was to be treated as such.
In other words, they were to see him no differently than they saw the brothers and sisters from their own Society.