In this first part of a series, I will explain and expand on MCU Scarlet Witch's powers, and how they will develop, and which elements from the comics I believe will be incorporated. Obviously the caveat is that these are theories of varying veracity, but I have tried to base them credibly within facts and lore.
KNOWN & HIDDEN
There's a misconception among some that MCU Scarlet Witch is merely a Jean Grey clone, this is fundamentally wrong, as it is based on the presumption that her powers have all been shown. They have not, a fact which Elizabeth Olsen has made clear.
Let's quickly go over the established powers in Age of Ultron:
The ability to move objects mentally. The extent of this will increase.
The ability to feel the thoughts of others. As Wanda becomes less introverted, she becomes more aware of others.
The ability to project thoughts, hallucinations and dreams into others. Currently she cannot see what she projects but that will likely change as she masters her powers.
ENERGY AND MATTER MANIPULATION
The ability to concentrate energy in Hex Bolts and alter matter. Again, the intensity and power will become more amped.
Age of Ultron Hexes:
These powers manifest in the form of Hexes. Misty energy is Mind Projection, "electrical" energies represent Telekinesis. And then there's the supernatural stuff we saw when Captain America encountered her. On top of that, Olsen has hinted that she can tell you where an object came from just by touching it.
But there's more; Wanda survived the bombing of her home because a bomb failed to activate, even with bombs going off around it. This is a textbook example of Wanda's probability powers; jamming a gun, making a bullet miss, etc. And, again, in the HYDRA experiments we see Wanda survive the seemingly impossible. Ultron even notices this, and when Pietro tells her about the bomb, Ultron says, "Now, I understand".
It's possible he simply meant strength of will, but I feel it's unlikely an AI would approach such a conundrum that way. He may have figured that Wanda somehow manipulated something to survive.
But why did Pietro survive the Hydra experiments? Simple, he was in close proximity to Wanda. Her probability powers are not cast or shoot from her hands, they are passive, and driven by willpower. Note that Pietro died when he was separated from her. Think of her probability powers as a finite probability drive, influencing things within a field around her, acting as an engine of her Hydra acquired powers. Elizabeth Olsen has stated she will be able to (and may have already done in the case of Tony Stark and Thor) see possible futures. Think about that.
Mind + Probability = Premonition of possible futures
Telekinesis + Probability = Destruction of even Vibranium
And various other combinations. It could also enable her to learn magic techniques very quickly.
It's the "probability engine" that is tied to her emotions, and it's what drives all her other powers. When Pietro died, we saw her lose control, as her emotions erupted in explosive fury. We will very likely see her wrestle with this in Civil War.
The thing with probability manipulation is it's so abstract Wanda is totally unaware of it. After all, how would you know you were doing it? Of course, this is exactly the sort of thing that Doctor Strange would figure out.
But, there is more, some of it right beneath our noses...
CHAOS & CHTHON
Where does Wanda's power come from?
The Mind Gem? Nope. That's Vision's power source, Wanda having the same source makes no sense, especially since she is not connected to the Mind Gem and her powers seem very independent of it.
The scepter unlocked latent powers in Wanda and Pietro, likely seeded by the Elder God Chthon, a major player in the Marvel universe, his sister Ushtur is one of the Vishanti, while the other sister, Gaea, is a sworn enemy who created the Demogorge, which forced Chthon to flee to another dimension.
Chthon is so powerful that he cannot escape his own dimension, he can only do so via mortal vessels.
But what evidence is there of his involvement in the MCU?
The scepter was given to Loki by the The Other, a name given to Chthon's mortal representative. But Chthon would not work for Thanos; The Other may only be a loose reference and name placing on a different character, or maybe he was a spy, either an unwitting puppet of Chthon, or a knowing one.
That's rather an elaborate train of thought, but back to something more clear and solid. Consider that Wanda uses powers such as telekinesis and other mind-based powers, yet uses her hands in spell-casting gestures to create hexes. These are not magic powers, so why the gestures?
In the comics Chthon left a fraction of his essence within Wanda, and, according to Agatha Harkness, that darkness merged with her own repressed dark side.
Given that Scarlet Witch contains a fraction of Chthon, it makes sense that the hand gestures of this legendary mage are imprinted. Think of it as software still awaiting the "magic plug-ins". As Wanda masters her powers, Chthon may grant her new "gifts".
He called her a "daughter of Science and Magic".
The greatest of these being the ability to use Chaos Magic, the ultimate dark magic, hugely powerful, and rather handy if you are trying to stop a powerful mad titan. It's powerful but fraught with danger, channeling so much Chthonic energy is risky to the user, but Wanda may well be forced to "hit the throttle". That may even be Chthon's devious plan all along. He is known as "the shadow that furtively creeps behind God".
Of course, the MCU version of Chaos Magic may well be very different, it may even be invented by Wanda herself by combining various abilities, making her possibly it's exclusive practitioner in the MCU. Consider that the Infinity Stones are all about order, Chaos is the antithesis of that, making Wanda perhaps the best-equipped Avenger to fight Thanos.
Wanda's powers are tied into her character very closely, and we will actually see Wanda learning about her powers, and in doing so learning about herself.
Whereas Strange's gift is an ability to study, analyze, and then utilize knowledge, the talents of a scientist, Wanda's gift is creativity, she approaches her power in the manner of an artist. Another contrast with Strange is that whereas he was taught by the Ancient One, Wanda is self-taught, she's an auto-didact. It's a core part of her character, and it's her character I'll be delving into in my next article.