Living Minato
So, Lightning Bunshin solos?-> stated twice to have a IQ > Shikamaru
-> stated to be the best analytical fighter in the manga
-> stated to be superior to Lee(a taijutsu master) in taijutsu
-> stated to have a Sharingan on Itachi's level
-> soloed the main antagonist of the war, said antagonist which killed Minato/Kushina as a kid.
Yet still underrated. Narutobase lol