Which story I pick for the Writing Challenge?

[APM]

So... I will join the 30-Day Tapas Writing Challenge, but I want to know which of my old projects would suit better for this opportunity. Here are the concepts:

1-The Sky Travelers:
Basically my manga project, I'll just continue the story in another format.
(Fantasy, Drama, Adventure, Steampunk)

2-Reflection:
Hana, the girl who can pass through mirrors, the mystery of missing people and the inverted world.
(Drama, Mystery, Supernatural, Sci-Fi)

3-Underworld - A Brazilian Sci-Fi Tale:
Crime rises, stronger than ever. A special police department is created to silence all the criminals possible.
(Action, Drama, Cyberpunk)

4-LoNELY The Game - Kingdom of Shadows
(backstory of my game project) The early days of the Kingdom of Soóron, the legend of the Knights of Light and the fall of the Star of Light.
(Fantasy, Medieval, Adventure)

Thanks for the help!

[Down_the_Rabbithole]

Reflection snagged me immediately! That sounds so cool!

[APM]

This one really has a very interesting concept. I'm just a little confused about how I'll guide the plot...

[Down_the_Rabbithole]

When I have trouble with plot, I make a flowchart. I type down the events I want and put down questions between the arrows. Example:

Person A runs away from person B ----- Why? ----> Because person A knows person B is a homicidal maniac. --- How does person A know?--> Person B killed person A's brother.

I wish I could show you a better example, but that picture glitch is preventing me from showing you my flowchart. Hopefully this helps you organize your thoughts because that Reflection idea sounds so cool!

[APM]

Thanks, that's a great advice! I'm studying some writing techniques before start it. Also studying about the setting, because it's supposed to be in Osaka, Japan. (I did this concept when I was planning to travel there, but unfortunately it didn't happen. At least I'm still studying Japanese).