Could it be possible that susanoo is just a embodiment of the users will over charka. As in one has complete control of charka to an extent to their mastery and transform it into anything. the bijuu's are living charka hence their abilities to transform their host into monsters. chakra is the currency of power. But uchiha without the extra will/mind controlling the charka , can manipulate their charka to form endless objects and also control charka around them. like bijuu's because their charka.
Maybe the idea of the Uchiha's third ability is that they are given free will to become anything they wanted to without the burden of becoming a jinchuuriki and trying the befriend a crazed monster. their whole lives they must endure pain and hatred to obtain this feat, a journey of a true human. the ultimate test of becoming a true person.
If itachi could've been king but he one got aids, second he and a few saw that a life beside your friends was more fulling than one who controlled their friends. of course mans sins will always win. thats why he had to wipe out his clan because their was potential evil or path that one will take at the end.
Madara was able to form a susanoo with no eyes so once obtaining it unlocks semi perfect control of all charka.
Maybe the idea of the Uchiha's third ability is that they are given free will to become anything they wanted to without the burden of becoming a jinchuuriki and trying the befriend a crazed monster. their whole lives they must endure pain and hatred to obtain this feat, a journey of a true human. the ultimate test of becoming a true person.
If itachi could've been king but he one got aids, second he and a few saw that a life beside your friends was more fulling than one who controlled their friends. of course mans sins will always win. thats why he had to wipe out his clan because their was potential evil or path that one will take at the end.
Madara was able to form a susanoo with no eyes so once obtaining it unlocks semi perfect control of all charka.