I play a part LaLiga Team and needed a useable stay back CDM as addition to my offensive minded second CDM Nkunku in an 4-3-2-1 formation. For me useable in this context means he needs to play more like a third centre back. He has to be able to make headers and must be physically strong, while being able to play passes who are not complete garbage. For me Casemiro is everything I just mentioned. Expecially his passing and his quite smooth ball handling (for a man of his size and agility stats) were suprisingly very nice.
Only bad point about him is the strange shooting upgrade he got. I played him about 20-30 games and I never once shot at the goal with him, and when I tried using him more offensive than stay back CDM he was useless, because he is way too slow for being a box-to-box midfielder. Apart from that I think he is very much usable.
+Defense
+Physicality
+Passing
+Dribbling is suprisingly not that shitty
-Speed
-senseless shooting upgrade (my be good if you are able to use it)