so after some min-maxing tries i figured out that the Soul Shroud and the Vile Shroud Nodes in the Reaper Specialization Tree do not work properly.
Sould Shroud: Occording to the Tooltip you should get 4 armor per Point of int. In my current build i have 113 int, so i should get 452 armor. For some reason i get an exorbidant amount of armor to the Point i would call it broken.
Vile Shroud: It should give me the same amount of armor, for necrotic and Poison protection, but those node seem to not work at all.
If i spec out of Vile shroud i get the exact amount of armor that i should get (452).
So i guess the Vile Shroud Node just gives unintended high amount of armor instead of the described necrotic and Poison protection
For refference here are some screenshots (the % protections Count is different because i took the screenshots in different waves in Arena)