Student_Of_Culture
Prefer you don't make a NPC. Its annoying writing wise when some rando reaches 100% affection. The disjointment is made worse knowing that the MC made them as an ideal. I hope the MC will come back to this world. Or at least leaves something to help recover the world. Since he can mindcontrol and hack his way into hidden technology.
I think he should upgrade the nazarick too as this will be his base in the new world so i think he should upgrade the defenses as well as increase the stats of the NPC's may be upgrade their race and give them better equipment. Also he can increase the low grade NPC's to have more mob characters as unlike momonga he can not create undead. Also it's better to horde things like scrolls, potions and gold as anyway these things would not matter much here when the game is about to go down but in the new world these things would be very helpful. One more thing i would like to recommend the author is not to brainwash NPC's and let them be loyal to mc because they respect the supreme beings and because of the relationship he built with them. That would give their character more depth rather than just being some brainwashed doll.