When I first wrote my story, the main villain was introduced very early. Now because I split off the 1st act as it's own book now the Villian is in like two scenes the very beginning and end of the 1st book. He is more in the background that led to the circumstances for the main character but isn't directly involved in the main plot whats going on. If I leave the main villain in there he will be a big question mark for the reader "Who the hell is this guy?" as for the sequel. He isn't really involved in the main plot but more just background noise. The MV has a bigger take on sequels for the entire series aka the puppet master sorta speak. There is another antagonist but more of a cannon fodder type of villain for the MC in the first book which he interacts with the majority of the time. Just debating to keep the MV in the 1st act as a warm-up for the 2nd book or just take MV out completely just introducing him later on.