This was a novel that I read back in the mid/late 90's, although I'm not sure when it was actually written (the library I read it in had a collect that went back a ways).
The two notable features that I remember is A) the ultimate big-bad of the story actually turned out to be some kind of AI that was actually trying to follow it's instructions for keeping humanity safe but had drawn the conclusion that the one of the bigger threats to humanity was humanity itself (I believe it'd also been damaged some way and I don't remember how it managed to get control in the first place).
I don't remember much about the hero himself but I do remember that one of the party members was actually a shape-shifting assassin that could take the form of it's victims. The technology of the setting included teleportation and transmutation but organic life could only be a transmuted once. This became a plot point because the protagonist faction was aware of the assassin and as part of a trap laid in the climax of the story (where many guests where teleporting into an event) transmuted each arriving guest into themselves. 99% of guests were not affected (being transmuted but into themselves meant nothing) but it effectively trapped the assassin in the last form that it had taken.
I also seem to remember one of the party member was a female genius of some kind but had been genetically engineered to breed children so could only function if pregnant.