You could also use the Vector X when using the Platform behaviour. So for instance when an enemy gets hit you could set the Vector X to an amount, say 200, for this example (try out a higher or lower amount to see the impact),
200 is a positive number so the enemy would "dash" off to the right - meaning you should check before the enemy takes the hit if the player/weapon, is left or right from the enemy that gets hit.
If the player is on the other side of the enemy, on the right (I'm guessing it's a sidescrolling platform game), and the player hits the enemy to the left side - use -200.
Hope that helped a bit