Did Kishi explain this?

[Omnipotent]

Did Kishimoto ever explain how Obito was able to use Kamui without even activating his MS? Also, did Obito take control of the Kyuubi with 3 tomoe...? Did Kishimoto explain that either?
Just wondering cause I don't think that was ever cleared up for us

I don't think he needs to. Naruto's doing well enough while being full of plotholes.

 

[Tartarus]

refer to drakengard's and ibon's posts

 

[Makoto]

Obito's MS was never shown because his identity was a secret, remember? Revealing his MS would've told everyone that's Obito's eye and possibly revealing Tobi is Obito. Kishi didn't want that until the chapters leading to revealing his face.