1. He has sharingan so he copied amaterasu from itachi
2. He has sharingan, so he copied the absorption from madaras
3. The sussanoo changed because of the chakra being absorbed by preta path (the absorption technique)
4. He used chibaku tensei with naruto, so he does know how to use that
LMAO sharingan can't copy kkg. His own MS gave him amaterasu. LMAO Madara wasn't even using preta path to counter Amaterasu nor has Sasuke ever seen madara use it. why did you bring up chibaku tensei?
lol you are obviously writing your own manga at this point because the bold is fanfictions so not even going to bother. sharingan copying chakra abosorbtion has to be among the dumbest things ive read in this forum and thats saying something considering the crap most poeple post here.