Spoilers to the AU

As above.

-The reason why Hummel joined Dana’s detective office

Hummel had received a request to deliver a package to Baron Iclucia, who was visiting Romn to give information on the Nameless Slasher. Said package was in fact an explosive trap meant for Hummel, but the baron shielded him from the explosion and while he was dying from it, he requested the transporter to “deliver help to his daughter” if they ever met. In Hummel’s terms, a transaction was done at that moment with the price being that of Baron Iclucia’s life, so once Hummel saw Dana’s name plate on the table when he was being treated, he took it on himself to help Dana in what she does.

The Red’s identity and actions:

Adol, which is obvious for us but not for the people of Romn. His bookworm self is exaggerated as a guise to prevent him from being identified as strong and therefore gathering suspicion. The baggy clothes he wears most of the time covers him up physically(deuteranopia is not faked). The Red both causes and resolves “mysterious” events in the countries he visits; the events were already underway by the time he arrived, but when it was solved, it wasn’t prominent enough to cause mass reaction, so they were called mysteries. This includes that of the Nameless Slasher, since Adol travels to Romn with the aim of solving that. However, most of the other events were staged by Romn for their further expansion, so once the Red shows up in Romn there’s a search being done to get rid of him, although what it means is basically ‘dispose of whoever gets turned in under the suspicion of being the Red’ for the high-ranked officers.