Black Stories ~ Touhou Edition - Case 20: Down to the bottom of Misty Lake!

[axman36]

Did Shou not know the darkness was being emitted by Rumia?

Did Shou block a bullet thrown by Rumia?

Did Shou block some type of item thrown by Rumia?

Did she even know Rumia was there at all?

[Thaws]

Did Shou not know the darkness was being emitted by Rumia?

WRONG ASSUMPTION, in fact, there's two wrong assumptions, one is that Shou did not know Rumia was even there. Now, figure out what the other assumption was.

Did Shou block a bullet thrown by Rumia?

NO

Did Shou block some type of item thrown by Rumia?

NO

Did she even know Rumia was there at all?

NO

[axman36]

Shou did not even notice the darkness at all?

So she was shielding herself from what she thought was an attack but was really Rumia's orb of darkness?

[Pesco]

Tipofthetonguewealmosthavetheanswer

Only locking this once it's solved.

Brief summary
Working off that Shou doesn't know Rumia at all, she sees a ball of black coming at her while she's minding her own business. Shou thinks it's a harmless physical attack so she blocks it with her arm.

Did Shou see a threat?
Did Shou see an unnatural object?

[Prody]

Did Rumia throw projectiles at Shou of some sort?

[Thaws]

Shou did not even notice the darkness at all?

NO

So she was shielding herself from what she thought was an attack but was really Rumia's orb of darkness?

YES Good job.

Did Shou see a threat?

YES

Did Shou see an unnatural object?

Well, you already know what she saw. It's magical so I guess it's not unnatural, so NO.oh wow, did I said not unnatural o_o. I mean it's probably unnatural since it's caused by magic, so YES.

Did Rumia throw projectiles at Shou of some sort?

NO

[Prody]

NO, she wanted to shield herself from something physical, but if it wasn't Rumia herself, what can it be?

Ah, I thought her darkness can't be considered physical... it was the first thing that came into my mind.

The pagoda's light has nothing to do with the case.

I also felt quite confused when reading this since Sakana mentioned that this appears in the answer.

Anyway...

Shou was flying over the lake, holding her Pagoda. Nearby, Rumia was heading towards Shou with intention to attack her. Shou did not notice the ball of darkness until it was close. When she noticed the orb, the attempted to defend against by shielding herself with her arm which was holding the Pagoda. Shou did not know Rumia was in the ball of darkness at all, she was caught off guard when Rumia directly attacked her. This attack startled Shou and caused Shou to drop her Pagoda. She then dove into the lake below to get the Pagoda back.

 :X

[Thaws]

CASE SOLVED!
Enough details have been uncovered and brought into connection to declare this case as solved. Please wait a bit for
post-game summary.

Shou was flying over the lake, holding her Pagoda. Nearby, Rumia was heading towards Shou with intention to attack her. Shou did not notice the ball of darkness until it was close. When she noticed the orb, the attempted to defend against by shielding herself with her arm which was holding the Pagoda. Shou did not know Rumia was in the ball of darkness at all, she was caught off guard when Rumia directly attacked her. This attack startled Shou and caused Shou to drop her Pagoda. She then dove into the lake below to get the Pagoda back.

YES

The Byakuren crew has already settled into Gensokyo. So, Byakuren decided to start getting to know other large parties in Gensokyo.
  She asked Shou to head towards the Scarlet Devil Mansion and have a chat with the occupants there. Shou brought her spear and pagoda just in case there was going to be danmaku battles.
  She was flying over the Misty Lake when she heard a voice from below, right behind her : "IS THAT SO~". She turned her head to look for the source of the voice, instead, she saw a huge, black sphere heading towards her at high speed! If you had a volleyball shot towards you, you'd block it without much thought, right? And that's exactly what Shou did. Since Shou has never seen Rumia before, she had thought Rumia to be some kind of huge cannonball. She sure was surprised when her palms went right into the sphere like there was nothing.
  She quickly realise it was just a sphere of darkness, so she tried to light things up with the light from her pagoda, but it wasn't in her hand! You see, when a person tries to block something, she opens her hands and push against it, right? But Shou was holding her spear and pagoda, and the items fell straight through the sphere with no one and no friction to hold onto them!
  The pagoda was a extremely valuable treasure, so Shou dove straight into lake in search of her treasures.

And this concludes the first Touhou Black Story.
The details in your answer are a bit-off, but all main points are discovered.
I've had fun being the gamemaster, though the process did not went that smooth, I hope you all enjoyed this riddle I made.

[Pesco]

Good game! Never again assume all the Touhous know each other

Get your post game comments in before I lock. New topic for the new riddle, which is mine

[Dead Princess Sakana]

Oh, nice job.

I admit that one was a bit mean, but it was totally reasonable and solvable. Thaws did a really good job creating this, and watching you guys dance around the answer was fun 

Never again assume all the Touhous know each other

That was definitely the best part and also part of the reason why I liked this riddle the most.

Also Thaws: You did well as gamemaster, really. You made extra comments when neccessary and gave correct answers. If you still think you made mistakes somewhere, well you'll have two more tries to do it even better soon, seeing as there are still two of your riddles left. 

A very nice finish for the first Black Stories thread, I must say.

See you all in the next thread, my dear players.