I want to make something that looks like someone is throwing a knife, and it acts like a boomerang. I want the arc of the weapon to have this shape:
http://mathworld.wolfram.com/Pear-ShapedCurve.html

with the caster as the point at origin, and the player's position at time of throw at the other x intercept. If it gets close enough to the player it does damage through script.

Basically what I'm thinking is that I equip my boss with two dwarven daggers, and have him teleporting around and such and occasionally a package fires that makes him stop completely and throw daggers. This is done by forcing an attackLeft animation and then the left dagger gets force unequipped through script, another dagger is added to the world and moved to the bosses hand, and then it translates to the next point in a matrix of points along the curve I linked to. When it translates to the next point it also does a 180 degree rotation about the Z axis to make it spin.Then he waits a half second, and the same thing happens with his right hand. He waits until the boomerangs get back to him, and then he starts dodging around again.