Devil May Cry I

As a matter of fact, Xi Wei was passive on this occasion.

Interference from the Demonic Roe could block the eyes of divine beings to a certain extent. After all, not even Aslan the Great Lion could see Zod back when he became the Tsujigiri, and that deity was much more powerful than Xi Wei.

That was why Xi Weixi did not notice the Demonic Roe hidden in Cecil's possession, and could only assume that he could not spit in certain places in the castle no thanks to the divine power of Kratos, the God of War that shrouded it (but it was actually in Cecil room).

The fighting had already started at the main keep when Xi Wei finally realized that something wasn't right.

Then, when he finally finished drafting the quest and assigned it to the Players, they had already understood what happened thanks to Kinley.