obito did all this for rin

[Shadow Phantasm]

Rin has always been his motivation so nothing new.

 

[Darth Uchiha]

It was more ideological, Rin was the catalyst that set him on his path.

 

[Kurama999]

Actually, he relies this doing was Madara plan on killing Rin.
Madara told him that he was fooled.
Just how do the zetsu told him about Rin & Kakashi at that location, and the ninja were puppets.
Rin did explained to Obito what's happen that Kakashi killed her.
That made Obito to return and to help Kakashi team to destroy Madara / Kaguya.

 

[AlphaScythian]

I dont know what reasons your faves have for doing shit they were doing but they're all fodders before Rin power.

 

[Rainbow Dash]

Obito's motivation was the death of a child in war, which is nothing new because we know that children have been dying in war far before Obito's era. Obito just happened to be the Uchiha who is most sensitive and the least experienced when it came to dealing with death of close ones, and that's why Madara took advantage of him.