Projectile Returnal

So, I am adding a Tinkerer class to Minecraft, for which I want the player to be able to use Wrenches to build robots or sentries, but they can also throw it. The throwing is what I have a problem with: I don't know how to make it come back. I want the projectile of the wrench to either hit an enemy and fly back, or to wait 2 seconds and come back on its own. Can someone help me with this? It'd be much appreciated!