Lexa Doig’s reveal that Talia is really out for her own endgame rather than pushing Oliver for his own sake sheds some light on Talia’s ambiguity.
After all, she does kill a lot of people, and she has been pushing Oliver to unleash his monstrous side on Starling City.
That said, we can’t really qualify her as one of the good guys.
So far in Season 5, Talia has been working with Oliver in the flashbacks to help him transition from a Bratva thug who takes out bad guys who cross his path into a Starling City vigilante who picks off the criminals on his father’s list.