The codex puzzle is part of the main questline, and requires the collection of all the codexs. When doing this quest, use your eagle's vision that way you can flip the codexs the way they are supposed to be. The easiest way I found to do this is, work on the outer edges first since they all have a red line that basically makes a box (like the outer edge of a puzzle almost).
From here look for the assassin brotherhood logos on the map, and flip the codexs to make complete them (making sure they are the right way). Finally flip the codexs according to the roads (the lines within the map, almost like river looking things). Its a pretty easy puzzle, hope this helps!
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.