Obito tried to destroy Konoha using the Kyubi 16 years ago. Why didn't he just leave from there once he had the Kyubi under his control? Wasn't his plan to gather all the bijous? Why risking to lose the Kyubi like that? And also, I thought he didn't care at all about this world (he didn't kill kakashi, why destroying a village?) since he's going to make a new world.