is "ent_enemy" a Pointer?
A Pointer can point only to one Entity!
Use one skill to identify the enemy:

#define Art skill21;
#define Art_enemy 1;

action enemy_action()
{
...
my.Art = Art_enemy;
}

then if you want to know if the hit is a enemy:

if (you.Art == Art_enemy)
{
...
}

Edit: This is lite-C, but it is no problem to convert...