uchiha onion was made by orochimaru

[obito uchiha the wraith]

i believe uchiha onion was an unfinished clone of an uchiha made by orochimaru and early zetsu cells. his purpose was to capture itachi during the time orochimaru still wanted itachi but he was a failed experiment so he was left behind. the new akatsuki guy took dna from madaras corpse and maybe even some blood from sasuke to finish making onion. when he finished onion was informed that itachi was killed by sasuke he felt shattered and confused because his life purpose is now moot.

 

[BLAZE]

most likely becoz he has yet to deactivate sharingan