Ok, so after playing with the Soku2, I have concluded....

Nothing new was added, except for the characters. 

In actuality... 4 new characters were added, but they had to replace the existing 4.

Remilia, Reimu, Cirno, and Aya can be replaced with Flandre, Momoji, Rin, and Mokou.

No new stages are added, which is a bit disappointing to me.

But enough with that. Let's go to the title screen!

It's purple. That's all I got.

Arcade Selection screen featuring the new characters

Oh yeah, if you win as one of those characters,

Their original counterpart will show up. Also gotta love that good grammar XD

The vs screen.

What's worth noticing is that the 4 new guys' sprites don't show up. I'm not sure if it's something wrong I did here, but yeah.

Flandre sprite. She should not be in a happy state.

Basically a Remi sprite swap.

I was actually expecting an original sprite like the ones from MUGEN.

Orin sprite. Her running animation is absurd. She also has some Cirno sprite animation stuff. (like when she floats down)

I do like when she turns to a cat.

Momoji sprite. A Youmu sprite swap and HOLY MOLY HOW CAN SHE LEARN FANTASY HEAVEN (the 1 hit ko move reimu has)??????????

Mokou sprite. I cannot tell which sprite swap that is.

Her moveset is like Aya's.

UPDATE: As I thought, they are custom sprites for MUGEN. (A fighting game where you can do anything) But honestly, the modder did a bad decision choosing these.

I'll show you the better sprites on another post because I'm almost at my 20 limit. :(

And yeah. That's pretty much it.

I know that there's another hisoutensoku mod, but it turns it to a competitive game. so yeh.