Kotario
Can't he just buy a single magic spell tome in the future and keep transmutating it to get different spells Then trick people into his slaves. He can become the hidden king, while his subordinates toil for him. He can also become an executioner working for the Royal Family. All kind of criminals will be sent. The mc level will increase, without any effort
good chapter, one small comment though, he went all on "no assumption, only proof" yet he is assuming a lot of things (like a day is 24 hours in faust...) also would have been nice to mention that its the same celestial bodies (e.g. there is a sun and just one sun around him. same for the fonna/animals....) it seems he's taking that as a given