Harry_Dresden
Hey author, if Alex can go to novel worlds, then you should defenitly have him go to the legendary mechanic universe. The tech they can take, the subordinates and wives he could get like Aurora. Also, the power system their lets Alex get his genes enchanced if he follows it. Which means those powers wont be demonic or magic, but 100% pure Alex that can not be taken away from him with something like an anti magic field or something. And if he recruits Black Star, he would have a subordinate who has his own system with all the advantages it gives him. He would essentially be a more powerful Hajime or whatever the guy he got in the second world is called