Board Thread:Naruto Discussions/@comment-28450860-20160622145346/@comment-5547501-20160623103021

I don't know about Tengai Shinsei, but Madara didn't teach anybody about Limbo because he wanted to keep it to himself as a personal trump card. His conversation to Obito atop the Ten Tails made it clear that neither fully trusted the other and both had their own reasons for what they were doing, and they would willingly sacrifice the other for their own goals.

Just prior to facing Might Guy, Madara did not want to use Limbo because he knew Obito could see it with the Rinnegan, so if he could have helped it, Madara would have never wanted the secrets of Limbo to be revealed to anyone.