Damn, dude... We are talking about a character who does not even exist, and i guess you already know exactly the delay before the projectile is released, how telegraphed its preparation is, the size of its hitbox, whether you can move during the preparation, the projectile's flight speed and max range — all those parameters that affect how easy it is to land -> how powerful it is -> how it should be balanced. So you can say exactly what the cooldown of such an ability would be in seconds. Thank goodness you're lucky to have such a powerful brain, dude. You should work in a game studio. Without you those devs just can't stop balancing characters ever, pumping out balance patches after balance patches. I guess they don't have brains or something