Blackened characters in anime

[DarkAngel]

would you like them to turn back after getting betrayed by others and facing the harsh reality?
i don't think it's possible. wei from the untamed is such a character and i want to save him

 

[Star_Of_Hope]

I think there are many characters like that. Even Sasuke and such characters will come under this category.

 

[Kaname]

When you say blackened does than mean permanently turned to dark side?
I don't think Sasuke fits there as he for back to the right track after sometime and I don't think anyone I know fits this description