I don't want to spell Aishikeru differently until we have something that either has a precedent or evidence behind it, or something that looks like an actual word. Ayshikel does not.
USE has been implementing systems that transcend borders (it pretty much is exactly an international government, which is part of why the corruption is such a problem). The witch trials concern more than just one nation, as the weird happenings that the witches are said to have caused are occurring all throughout Evillious. The Dark Star Bureau appears to be an international judicial system.
Nonetheless, there probably isn't enough to assume that he is in the Corpa Mansion. There's nothing saying he isn't, but there isn't much saying he is, either.