Itachi soloed:
Oro the legendary sannin
Kakashi the sixth hokage(he was stronger in that timee than the time he became hokage though)
Uchiha the genius clan(at the age of 13)
Nagato who had madara's eyes and rikudo's power (the one who destroyed konoha and a god like naruto had to defeat him with SM ,6-9tailed kyuubi and
rasenshuriken-besides when he was soloed,he was at full power and wasn't out of chakra like he was during the battle with naruto)
The sage mode kabuto who was stronger than oro
Deidara
Hoshogaki kisame,one of the 7 swords man of the kirikagure
Even fought the third ninja world war at the age of 4!!!!!!!!!!!!
Got approval from:
The god of shinobi hashrama senju
Another god,sarutobi hiruzen
Oro the sannin
Obito was even scared of him (a 13 year old boy)and accepted his conditions and stated he was a troublesome member of the akatsuki
The childs of prophecy and the gods of the world,naruto and sasuke chose the right path by getting motivation from itachi uchiha.
He doesn't need any approval from those blind people who can't accept the truth and see his success.

:Sparks::flakez: