(Warning: the following thread contains spoilers and dark stuff. Read at your own risk)
I want to share with you something that has been with me for a very long time. It started from a notion, gradually growing and taking shape. It became too big to present all my connected thoughts. Even now I'm still fleshing out the details, but the core idea remained mostly the same.
Now lets start from the very beginning: the "Red" Trailer.
We all remember the buildup of anticipation and the subsequent breathtaking fight. However, what I want to focus on are some details that can easily be missed or ignored.
First are the lyrics. It is generally accepted that each line refers to a different girl of team RWBY. What if that's not all there is to it? What if it refers to Ruby herself?
We can easily see the possible reason of her yearning. "Royal" can be interpreted as grand or great and, when put that way, "royal test" becomes a more ambiguous expression. What could be Ruby's trial? And what could "Black the beast descends from shadows / Yellow beauty burns gold" mean?
Next is the weapon. A certain letter brought my attention to the fact that they may have meaning.
Myrtenaster highly resembles Winter's weapon. It can symbolize Weiss' ambition to be like her sister. I can see her later wielding the sword of the Armor herself, embracing her own strength and independence.
Ember Celica requires a specific fighting style. Each shot accompanying the punch not only damages the opponent, but also is used to throw the next. It requires both hands else the user becomes weaker than Junior's henchman.
Gambol Shroud is still a mystery to me.
So what about Ruby? Early design had her using a pair of claws. It is a weapon with a likeness to a beast. And the Crescent Rose? It's a scythe. Tool of farmers...
...and the avatar of death.
Also if death were to choose a gun it would definitely be a sniper riffle. I can totally imagine it camping all living beings.
Last clue from the trailer I want to talk about are the petals or, more precisely, the fact that they come out of the Grimm. I saw a theory of the teaser being a dream sequence. It would change the way it can be perceived. We would get Ruby struggling with her inner demons or perhaps a subconscious fear.
But how could Ruby have become part Grimm? Whoever was the cause is a very important part of the story. Who could it be? "Yellow" Trailer gives us a hint: Raven.
Now let me tell you a story:
During her time in Beacon Raven is trying to impress Ozpin, a person very important to her. However his degrading attitude (remember his speech?) causes her frustration, and his fixation on Summer directs it toward her teammate.
Then Taiyang proposes to her. She is overjoyed, but at the same time anxious. When Yang is born her insecurity and feeling that she will ruin that happiness reach their climax. She runs away. However she can't completely give up.
And then she sees Summer and Taiyang together. All reason leaves her that moment. She decides to kill her most hated person in the worst way she can imagine: by a Possession-Type Grimm.
She ambushes her successfully infecting the woman, however Silver Eyes protect Summer. Or so it seems as the Grimm makes its way into the womb...
Raven leaves, unaware. Later she sees Summer, now with a child. She waits for a chance to off her for good until years after at the place where Summer's gravestone can be found...