Board Thread:Naruto Discussions/@comment-45851667-20200520192705/@comment-32685487-20200523202431

Its still a crow and that's still a Sharingan. To think the crow needing 10 years means Shisui needs 10 years is definitly a fallacy in logic. Shisui clearly used it multiple times after he was 6 years old, enough to know how it works and have a name for it. He was planning to use it again at age 13. Shisui himself does not need 10 years for the techs recharge. Also it was heavily implied to be Koto that he used against Mukai, the Byakugan user. and that was the same year he was going to try to use it on Fugaku too.