This is personally my favorite marvel movie, the villain has a very detailed backstory and she is far more powerful than anyone actually realized. See strange seems to have been training very hard because his abilities are far greater than before. You get see how well Wong has taken to his role as sorcerer supreme.
This movie has an amazing way of telling how Wanda snapped and you can truly see the transformation from hero to villain. With her experience leading up to the attack on the fortress you begin to realize that she has been aware of her true abilities and trying to avoid apocalyptic mayham for some time, the way she reveals her true powers to Dr strange is something of a nightmare. Wanda is clearly the star of this movie, by far my favorite villain this far.
Dr strange and Wong appear to have been on track to building a formidable defense against godlike beyond and for the most part they did very well, Wanda is just entirely to powerful for a small army of highly trained sorcerer's .
So pretty much, this movie is about wanda trying to leave her universe due to total heartbreak and she simply does not have the will to stay any longer, so she explores her abilities to find a way to leave but unfortunately her actions end up drawing Dr strange into the mix and once he finds out her plans he can't allow her to follow through with her plan for fear it would fulfill a terrible prophecy either killing everyone in the multiverse or ruling them. There are quite a few cameos along with some surprise action scenes all drawing to a very surprise ending that I didn't see coming. I love this movie my wife loved it and I highly recommend seeing it, thank you Sam for moving marvel into this dark phase they are starting to explore.