Board Thread:Theories and Speculation/@comment-33256714-20171005000302/@comment-734582-20171007125754

Indk21 wrote: What about Madara's Rinnegan? I think it's important to remember Tobirama's words here: the Sharingan is a manifestation from chakra in the brain. Susanoo is manifested initially by dual Mangekyou, but once manifested it no longer needs the eyes. According to the legend, Susanoo was borne from the nose, so i guess it makes sense that it's technically not a dojutsu.

In other words, Susanoo is a technique that originates from the brain, not the eyes.