Folks who still think the technicality of a question mark in "Obito?" accounts for Tobi not at all being Obito,
Make some sense. Tobi has been making clear references to experiences with Gai, Kakashi, and even talked about what Minato, Jiraiya, Nagato had entrusted to Naruto. He is Obito, in the sense that he has the body and mind as well. If body and mind are of one person, he IS that person (don't say some other soul is in his body, that argument has no merit)
He IS Obito, who probably got corrupted and is seeking revenge and for unknown reasons wants to implement Moon-eye plan. These details will be revealed in next chapters (you don't say that, but I'm still saying

)