Shadow Avatar is a convenient ninja technique developed by the second generation of Naruto, which is widely circulated in the forbearance world, so many ninjas will know it.
Willing people are:
Senju Tobirama
Sarutobi Hiruzen
Wave feng shui gate
Kakashi
Naruto
Jiraiya
Sasuke
Inuzuka Kiba
Muyewan
Borruto
leech
Itachi Uchiha
Orochimaru
Uchiha Madara
Deidara
Waiting for ninja