We know that the big bad for Arrow Season 6 is going to be a group of villains. The group seems to be specifically built to mess with Team Arrow and will include Katie Cassidy as Black Siren, Kirk Acevedo as Richard Diaz/Dragon, Michael Emerson in an unnamed role, and David Nykl returning as Anatoly Knyazev. And of the group, Anatoly brings what might be the most psychologically challenging opponent for Oliver Queen.
Where Black Siren is Laurel Lance, she's not Oliver's Laurel. He knows that and may be hopeful that some of his Laurel exists in her, he knows the difference. But Anatoly was a friend, brother, and mentor to Oliver. They survived Lian Yu and Oliver respects him still. Stephen Amell talked with EW.com about the relationship between the two men:
"Anatoly has an interesting power over him that I don't know a lot of other villains — if any villain at all — has ever had. Oliver didn't kill Chase for a very specific reason, because that's what Chase wanted, but he tried to kill Malcolm, and he killed Slade once upon a time, and then put him away in prison, and then he went on this anti-killing thing, but he still killed Ra's al Ghul and still killed Damien Darhk. Anatoly is this weird grey area of a guy that he loves and respects too much."
And if you think Anatoly isn't a foe on the level of those others, lets not forget that in the comics, he is the KGBeast. They could always upgrade him a bit.
Arrow returns October 12th at 9 p.m. ET on the CW.