Unique abilities?

So I made some textures for a class, all of its code is under the <!-- thing...
I really want to make its ability charge up like the shuriken, except sort of the opposite. It would make the character slower as they charge it but the longer they hold the more shots there would be.

That doesn't really NEED to be part of it, but I would really like to have it so it would make the projectile one of 3 projectiles, so it would be different. I know how to make the projectiles change but how would I make them do different things (damage, piercing, etc.)?

If anyone could help me that would be super great, not asking for someone to just code it for me, but at least point me in the right direction.
Thanks

Well make sure to use a new slot type when you add the item. Every type of item has a different slot type. For example each ability has a different slot type. If your using Phoenix or doomed source alot more slot types you will notice all the new abilities have done this. You also have to (once you give your new ability this slot type) tell the class to use that slot type which you have to do in dat2 (I think its dat2 I forget just change it in the xml for classes) and in the client.