VERSE DROP FOR UCHIHA ITACHI
"DECEIT IN HIS SMILE; BLOOD ON HIS HANDS"
Canon-compliant. Main verse.
"TREACHERY IS A RAGING INFERNO"
The Uchiha massacre never happens, or it happens but not by Itachi's hands. (This will be marked with #;massacre in the verse tag). When ordered to kill the clan, Itachi refused to kill his family and friends even if he saw the wrongs of their actions. With the threat of a coup d'etat by the Uchiha, and with Itachi on their side, Itachi was targeted by Danzō.
Understanding that he no longer has a home in Konoha, Itachi leaves and is now a missing-nin.
non-massacre verse: Itachi is said to leave Konoha because of nefarious actions that were never stated. When someone asks what they were, it is only said that Itachi agreed to the coup d'etat and even wanted to lead it with his father.
massacre verse: Itachi is accused of the Uchiha clan massacre and is said to leave Konoha because of his actions.
"TO BE STRONG IS TO FORGIVE"
This is a verse that I had to do some mental gymnastics until I got it to finally work a bit. (and I don't even know why I put so much time into this).
Shisui is one of those summoned by Kabuto's Edo Tensei. Kabuto modified Shisui's body and gave him eyes to work with because Shisui was brought back without eyes/blind.
After getting out of Kabuto's control by using Shisui's eye that he had stored in his crow, Itachi sought out Shisui and gave him back his eye. Both out of Kabuto's control, they went back to him and, with Shisui's Kotoamatsukami, Kabuto turned good.
Kabuto sent back everyone to the Pure World except for Itachi who chose to stay until he could rekindle his relationship with Sasuke.
Orphaned at a young age, Itachi grew up having only Sasuke to love. His uncle took care of them until Itachi turned 18 and moved out, taking Sasuke with him. With a career as a world-renowned lawyer, Itachi had enough income and more to give Sasuke a comfortable life until he graduates and finds his own path.