Who has caused the most harm to the Ninja World?

[shelke]

^ Yes. Both Uchiha and Senju had shady pasts, no doubt about that. Obito didn't even plan to revive Madara. If you remember, he chose Sasuke as a replacement quite early on. Him following Madara was his own choice. I suppose Rin's death jilted him. In his defense, I would say that whenever one is faced with the death of a loved one, one alters his/hers philosophies on life drastically. He chose to follow Madara's and the Nation's provided the perfect opportunities.