there's an implied itsuno vergil backstory pieced together from scraps of canon information. Naturally it holds very little validity, but I really wish it were established canon, because it's my favorite one.
Canon - when vergil and dante are very young, they're attacked by vengeful demons out for sparda's blood. Their mother, an ordinary human, manages to save them at the cost of her own life.
Not canon - Dante sees his mother's sacrifice as an act of incredible strength, and this is what sets him on his belief that humans are at heart more powerful than demons (just not physically). Vergil sees this sacrifice as an unforgivable failure; the demons who attacked were very weak by comparison, so the fact that his mother died to this kind of low level scum sets vergil on his path of total contempt for humanity.
Canon - when very powerful demons in the DMC universe die, their souls are reshaped into a powerful demonic weapon that represents their true name and their origins (bonus fact, sparda was so powerful he could revoke a demon's true name. This was some serious ****, and was why all demons feared him once he rebelled)
Not canon - vergil is a very powerful demon in the DMC universe, and he died. When he died, he became the devil bringer, and lay dormant in yamato. His contempt for weakness was so powerful, he refused to allow himself or his sword to be used by unworthy demons, so when it was picked up by an ordinary demon in hell, he shattered himself to prevent his own use.
Canon - the demon then carried the scraps of the broken yamato to the human world, which he used to wound an infant nero, before being captured by agnus and having the shards of yamato taken from him.
Canon - Before DMC3 there is a long period of time where vergil and dante don't see each other, and when he appears again, it's implied that vergil no longer gets along with dante the way he used to, and is out to cause some serious ****
Not canon - given the timeline, this "out of touch" period is the only time where vergil could have shacked up with a human woman to give birth to nero (also assuming that he actually is nero's father). During this time he meets a woman that somehow restores his faith in humanity, and out pops nero. He starts settling down and puts away his sword to live more of a family life, like sparda did. One day demons attack unexpectedly, and he's not prepared to defend his family. He's defeated, his wife killed, and nero missing (presumed dead). This reignites his earlier feelings from when his mother dies and he goes into a full downward spiral of resenting his "weak human half". This is his motivation for the events of DMC3, where he seeks to gain sparda, and use the power of the sword to alter his own true name to no longer acknowledge his human half, thereby becoming a full demon.
When vergil impales dante at the top of the power and makes the comment "without power you can't protect anything" vergil isn't talking about dante's inability to protect himself, vergil is actually reflecting on his own inability to protect his family.
Canon - nero's arm changes after a demon holding a strange weapon wounds him as a child
Not canon - that demon carried the dormant devil bringer. On contact with nero's blood, vergil's soul recognized nero's heritage and his strength, and bound to the wound, transforming his arm and establishing a link between the arm and yamato.
Canon - when vergil and dante are very young, they're attacked by vengeful demons out for sparda's blood. Their mother, an ordinary human, manages to save them at the cost of her own life.
Not canon - Dante sees his mother's sacrifice as an act of incredible strength, and this is what sets him on his belief that humans are at heart more powerful than demons (just not physically). Vergil sees this sacrifice as an unforgivable failure; the demons who attacked were very weak by comparison, so the fact that his mother died to this kind of low level scum sets vergil on his path of total contempt for humanity.
Canon - when very powerful demons in the DMC universe die, their souls are reshaped into a powerful demonic weapon that represents their true name and their origins (bonus fact, sparda was so powerful he could revoke a demon's true name. This was some serious ****, and was why all demons feared him once he rebelled)
Not canon - vergil is a very powerful demon in the DMC universe, and he died. When he died, he became the devil bringer, and lay dormant in yamato. His contempt for weakness was so powerful, he refused to allow himself or his sword to be used by unworthy demons, so when it was picked up by an ordinary demon in hell, he shattered himself to prevent his own use.
Canon - the demon then carried the scraps of the broken yamato to the human world, which he used to wound an infant nero, before being captured by agnus and having the shards of yamato taken from him.
Canon - Before DMC3 there is a long period of time where vergil and dante don't see each other, and when he appears again, it's implied that vergil no longer gets along with dante the way he used to, and is out to cause some serious ****
Not canon - given the timeline, this "out of touch" period is the only time where vergil could have shacked up with a human woman to give birth to nero (also assuming that he actually is nero's father). During this time he meets a woman that somehow restores his faith in humanity, and out pops nero. He starts settling down and puts away his sword to live more of a family life, like sparda did. One day demons attack unexpectedly, and he's not prepared to defend his family. He's defeated, his wife killed, and nero missing (presumed dead). This reignites his earlier feelings from when his mother dies and he goes into a full downward spiral of resenting his "weak human half". This is his motivation for the events of DMC3, where he seeks to gain sparda, and use the power of the sword to alter his own true name to no longer acknowledge his human half, thereby becoming a full demon.
When vergil impales dante at the top of the power and makes the comment "without power you can't protect anything" vergil isn't talking about dante's inability to protect himself, vergil is actually reflecting on his own inability to protect his family.
Canon - nero's arm changes after a demon holding a strange weapon wounds him as a child
Not canon - that demon carried the dormant devil bringer. On contact with nero's blood, vergil's soul recognized nero's heritage and his strength, and bound to the wound, transforming his arm and establishing a link between the arm and yamato.
