Board Thread:Naruto Discussions/@comment-27615170-20170519084657/@comment-734582-20170615181339

Starscream1998 wrote: That's really nice and all but being the odd kid out really doesn't excuse leading an organisation like the akatsuki, initiating the bloodline purges of the Hidden Mist, basically making Naruto and Sasuke orphans, leading a group that killed all but 2 Jinchuriki, reviving the Juubi and initiating a war. And his motivation was what exactly...oh yeah that teenage crush. We already saw why: Because Obito saw Madara's words proven right, right before his eyes. Where there are winners, there are losers. He gained power to do something but couldn't help anyone with it. As he gained even more power with the Mangekyou and a body to move around once more, he lost Rin.

Madara then showed him that he could create an ideal world, easily. In a crucial time of pain and bitterness, Madara fed him the necessary ideology to turn him. Which is exactly what Obito did to Sasuke.

As to Obito attacking the village, there's good reason to think it was intended as a suicidal mission. We learn later he was tagged with a Cursed Puppet Seal which prevented him from killing himself. If that's true, how did he find out? Well, the extremely dark implication of that line is that he tried to kill himself. Realizing he was nothing but a puppet, Obito's cynicism only became worse.

In the end, Obito's ideology was dealt a series of blows in rapid succession. He became disillusioned with the world and a deeply cynical man.

EDIT: in the manga, Minato's thoughts on Obito were not exactly super-inspiring. The only actual phrase he says is "we will be Hokage", which is pretty meaningless.