(Note: I cannot provide picture(s) at the time so bear with me)
Alright, so as of the latest chapter we get to learn more about the past during Obito and Kakashi's duel. Kakashi uses a Raikiri and right before Obito is hit we are shown a panel that zooms in on Obito's Sharingan. We assume he used genjutsu to show how it was like when Kakashi used the Chidori to kill Rin. But.....
What if this is also due to his body being made up of 50% or so Zetsu - material? That panel may have just been used to fool us. He could've also still been alive and talking from that "injury" because his Zetsu material is what's keeping him alive since it can regenerate. Also, when battling Fu and Torune he was shown losing his arm in the process but felt zero pain (I KNOW it's not just pain tolerance, I just know it). If this is true, he could've possibly been turned immortal as a result of the material, and after reading a recent theory by Sage of all Shinobi, it's possible that the Zetsu material is slowly taking over him and just might've corrupted him into becoming evil.
So, which sounds more reasonable? Tell me your thoughts and thanks for reading!