I don't make add ons, I modify them as I see fit. Like if a weapon is overpowered/underpowered, I fix the damage. If it shoots too slow, I make the bullet to go faster. In the case of the hidden blade, it swings like the sword, where it goes continously, firing way to fast with too high damage. Instead, like Space Guys TF2 weapons, I want it to roll its animation, and take around 5 seconds before you can fire it again. That way, its not completely overpowered, or a main weapon by any mesure.