For A Plague Tale: Requiem, I have read on a few sources that you can't get all the skills upgrades in one play-through. You need to play a new game based off your last save, called a NG+ game. I managed to get all the skills upgrades in 2 play-throughs, but I can't find conclusive guides about what triggers these.
There are different ideas around the web (Youtube, mostly) about how to achieve these skills, and the following so far seems to have the best results for me:
* 0 to 25% kills - Prudence * 25% to 50% kills - Opportunism * 51% or more kills - Aggressive
There is also references that you can level up Opportunism by using the environment (tar pots, rats, etc.) to destroy enemies, but for me that is inconclusive in all 4 of my play-throughs up to now.
Does anyone here have a complete guide to do these skills upgrades, and which parts of the game is the best to use for leveling up anything except Aggressive skill? For me it was Chapter VII, Felons. I also did not do too badly in Chapters III and VI. Anyone else have nice areas to level up?
Furthermore, how does the game calculates when to progress the level? It appears to me that it is when you pass a section you cannot return to, and that does make sense to me. Thoughts?