The Offer

A moment ago, Reiji instructed Shiori to just keep calm and he would help her how to deal with the priests. 

He's also communicating with Calliope using their Sense Link to ask about any information she has about the Church of Light.

Since Calliope is already a part of their group, Reiji decided to place her as his wielder so she could benefit from having a Sense Link.

Aside from that, she's already learning the Kendo from Diether so Reiji didn't really mind adding her. Though she's not his direct disciple, she would still be together with them for a long time and it would be better for Reiji if he's capable of sensing her presence as well. 

As soon as they entered the carriage, Reiji immediately sensed that the two Mythical Arcana owned by the two bald priests scanned Shiori's body.

Then, the priest suddenly spoke offering to buy the Arcana she has!

They felt more like a merchant than them!