Caizher controlled the ghoul and touched something on his wrist before a screen was projected on top of his watch. This watch technically works as a phone or computer back on earth. But it was more convenient as all the things that phones and computers were able to do were condensed into a simple and small watch
The ghoul sent a message to the other two City Lords and 'explained' to them what happened here. He also asked them to come in his territory for a meeting
Since the alarm was heard by a lot of people, it wouldn't do Caizher any good if he tried to hide the things that happened as it would just make the ghoul look suspicious
It would be better if people think that there is someone lurking in the dark that has enough power to hurt and kill the ghoul to the point that he will need the help of other City Lords