obito is a great and good and carring person for his comrades and for the village he just wanted to become hokage... As u know UCHIHA is the clan which holds up lot of love and when some thing happens to that love makes them angry and they turn into different person like sasuke who loved their parents and wanted to take revenge on his brother for killing them and when he learned the truth the love deep inside his heart took over him and he wanted to take revenge over the elders and danzo for causing a tremendous pain to his brother and he wanted to destroy the leaf.... like wise RIN HONOURA's death made obito to turn into a negative person as he loved and cared for her very much.... THIS WOULD CLARIFY ALL DOUBTS ..... K