Nice! I can't wait to see how this turns out!
I also got some ideas for the whole Hakurei Barrier thing:
Maybe you could have one command to use the barrier, and another to switch barrier modes. So far, I've came up with 3 modes:
1: Trap: Reimu makes a square-shaped barrier around herself, which can trap the opponent. It sticks around for about 5 seconds before disappearing. In addition, if possible, you could also have her projectiles ricochet around while inside.
2: Wall: Reimu makes a tall barrier in front of her. It sticks around for about 5 seconds before disappearing. It works a little differently than the other modes; when you first input the "use barrier" command, you get a glowing vertical line that slowly moves forward, input the command again to make the wall. Your projectiles pass through the wall. Very useful for walling out the opponent.
3: Portal: Reimu makes 2 barriers, one very close to her, and one very far way from her. They stick around for about 10 seconds before disappearing. She can go into either portal at any time simply by walking into one of them and pressing one of the attack buttons. Your projectiles also pass through the portals.
If you wanted, I could also help you out with the code to make it all a reality.