“Strong, attractive, stylish, and multicultural this name is also the Esperanto form of Mary… But Amara is also a Sanskrit name meaning immortal and a Mongolian name meaning peaceful, and is the Italian word for bitter (same root as Maryam and Miriam) occasionally used as a first name in the Latin countries.”
I’ve said elsewhere that flowers are used in Supernatural as a means of hinting at secrets, at things that are yet to be revealed. Early in the story of Supernatural, flowers were strongly associated with Mary. She often wore pink or white or blue.
Over the first few seasons the secrets of just how Mary was the source of the Winchester family’s narrative was revealed. She was revered mother, lost wife, hunter, and daughter. She was both loved partner and abandoned wife. She was the first to set off the chain of Winchester sacrificial deals. She was trained to be a hunter but desired only a safe and normal life. The audience’s and her sons’ perception of her changed over time as her story was revealed.

And here we have Amara, drawn into clear parallel with Mary by both her name and the visual motifs surrounding her.

Amara, too, is a woman of mystery and her story is a matter of perception, reinforced by both her forceful rejection of Death’s point of view and the distinctly purple tint (Purple is perception).

Here, now we have Amara, whose name has many meanings. She is immortal. She is peaceful. She is bitter. And she is Mary.
What is the aim of drawing these parallels between Amara and Mary, then?
Throughout season 9 and 10, we saw frequent visual motifs and narrative references to journeys. We had boats, airplanes, and cars, as well as stars and maps by which to guide them.

Now, however, we seem to have come to a “stop.” The end of the road.

When asked how to get rid of The Mark, the scribe of God said, “The river shall end at its source.” Have we reached the source? The end of the journey?
Mary was the “source” of the Winchester pain and dysfunctional patterns. Is the Darkness then the “source?” Did all things begin with her? And to end we have to return to her?
Why do the people the Darkness touches have an expiry date? Within hours, they die. If they are driven to “infect” others, why then do they die within hours.
I have to wonder if they are being called “home.” The darkness is calling what is hers home to her? She existed before God and Death. God said let there be Light, and the Darkness was banished.

Is the Darkness the source of humanity’s souls? Did God plunder her power and use it to create humanity, and then put her behind a lock that engenders bitterness at unfairness of your treatment and the belief that you have the right to claim others’ lives? A lock that is fed by the splitting of another’s soul from their body?
If so, then I predict that the story of the Darkness, her sacrifice, and her bond with Dean will parallel Sam and Dean’s desire to sacrifice everything to save the other. At some point, because of his bond with the Darkness, will have to directly choose between Amara and Sam. At some point, Sam’s tendency to sacrifice himself will be brought into parallel with the Darkness’ sacrifice to preserve humanity. And so, I predict that story of the Darkness will be the vehicle by which the Winchesters examine their dysfunctional patterns that have their source in Mary.
