Originally Posted by Wolverine
Izanagi is turning genjutsu into reality. Banbutsu Sozo on the other hand, was used to create the tailed beasts from the Juubi using a mix of Yin and Yang chakra.
Izanagi at best can be a derivative of BS.
But that's NOT what the original Japanese says though. It says Izanagi was the physical application that BS used to create all those things. Its the fire for the jutsu basically