Someone is Using Obito's Body really...

[Winter Savior]

This chapter seems to tell us that it is not Obito's mind in this body.

Obito was heedless , air-headed , late , open-handed ( he had a good heart ).
Tobi is reflexive , manipulative , punctillous , he lacks feelings.

But WHO/HOW/WHY takes his body if it is not obito's mind?

Nagato was a very nice shy guy as well, that didn't stop him a few years later once he'd gotten a new outlook on life from stabbing people with rods and beating people to near death.