ahh the joy of getting functions to pick - I've had so much fun with that
any how this is how I usually do it...
give your enemies a instance variable - then save the enemies UID to that variable .. when the enemy is hit - call the kill function and add the enemy.instance variable as a parameter.
in the function use "pick enemy by uid" and set the UID to pick to function.paramater and then do what ever you want to that enemy instance.