JAMES MASON (1909-1984). Suave British actor with a one-of-a-kind voice. One of my all-time favorite movie stars. Legendary in films like Lolita, Odd Man Out, Five Fingers, The Desert Fox, The Verdict, and so many others. As they say, they don't make 'em like that anymore.
Here's the thing, those personas were basically wholly different people - it was difficult to see Eurus in the others even after we knew. Playing different characters is an actor's JOB, and I don't think she ingeniously linked them together or anything. I might be being unfair, though. She was a good actor, but it might've been spoiled a little by my utter hatred of the last episode.