One thing that I'm wondering about is Obito's MS. If he's so flipping close to Rin and junk, then him hearing about/witnessing her death is probably what awoken it. I don't think he activated it when he was crushed (cmon, he just woke up his sharingan for the first time less than 5 minutes earlier, and he hadn't experienced any loss up to that point. If that's how he survived, then that's just bad storytelling). I'm pretty sure Rin was the one who awoke his MS. Now what I'm wondering is if Kakashi's sharingan is still connected and the MS awoke at the same time, or if it's independent. Which brings up the question, how did Kakashi awaken it, or if he had it all along, how did he learn he had it/how to use it?
Also, i read a theory that Zetsu is made from Madara's and Hashirama's cells. now that's something I haven't thought about. I knew the 1st was involved, but Madara, too? Also, Zetsu has a whole heck of a lot of storywork left, even after this fight. Don't think that this was the last major plot twist. Anyways, Even though I'm sure we would all like a nice, long, elaborate explanation on all of this, I think it would be much better, (artistically, and literatively) for him to reveal the backstory in flashbacks from Tobi's side. Like instead of him explicitly telling them how it went down, their fight will be interjected with scenes from the past told by either Obito or Madara.