Complex sentence: Like most Oomoto followers, Onisaburo believed that the original kami founders of Japan, were driven away by the kami of the imperial line and that placed him as challenging the authorities at the time, however, he had the ability to hide it.
Split into simpler sentences: Like most Oomoto followers, Onisaburo believed that the original kami founders of Japan, were driven away by the kami of the imperial line. This placed him in opposition to the authorities at the time, though he had the ability to hide it.