1. A Mary-Sue Uchiha that Itachi somehow missed during his massacre of the Uchiha clan, despite the fact Sasuke is the only other to survive.
2. An Uchiha who is even more powerful than Itachi.
3. Target practice for Itachi when he realizes he missed one.
The Suchiha also survived Itachi's massacre, developed Mangekyou Sharingan, has a horrible past, and makes me want to strangle the author.