One last thing to add for Tobi: When he was revealed as 'Madara', the plot ceased making sense at that point.
This isn't new that he's still alive, he's durable as fuck. People should re-read the Konan fight where he tanked about 240 billion bombs physically. The Jutsu lasts 10 minutes with 600 billion bombs so every minute, that's 60 billion bombs.
We know his intangibility lasts for 5 minutes, so he's passed the first 300 billion bombs safely. Then he has Izanagi which lasts for 1 minute, so that's another 60 billion bombs added to the 300, so he's passed 360 billion bombs safely within the 6 minutes. Then with the last 4 minutes, he has no choice but to tank it physically, which is 240 billion bombs.
The guy just won't die.
Obito is unkillable because he is Naruto's counterpart, he just doesn't stop no matter what until his goals and ideals are upheld.
The only reason Obito got beaten was because deep down he didn't want the whole Eye on the Moon Plan to happen and was just seeking a new meaning for his life after Rin died.
More important than that, he is the only person who knows enough about Infinite Tsukuyomi to help reverse it should they ever hope to beat Kaguya and release her victims.
That and a freaking Susanoo we are rooting to see ever since the whole eyes set has been hinted of becoming complete.
Other than Obito's name being similar to Naruto's, it took me a while to realize that both Obito and Naruto resemble swirls, one is a vacuum and the other is like a tornado/whirlwind. One is directed inwards and the other outwards.
actually almost all main caracters in the manga are representation of naruto and sasuke think about it if we put certain caracters we'll see a life cycle for naruto it goes like this :
naruto ->minato->kakashi->jiraiya->hashirama->hiruzen sarutobi
sasuke->orochimaru->madara->danzo , consider the main caracteristics of the caracter the rests are just details added for coherence.
imo almost every caracter in the manga is either naruto or sasuke with or without a certain trail(it's all about exploiting possibilities) :
-hard working sasuke = shuisi
-intellectual or wise sasuke = itachi
-the naruto that fell for corruption = gaara,obito, nagato,neji etc.....