public void Perform(ControllableUnit sourceUnit, ControllableUnit targetUnit)
{
AttributeBonus damageOutcome = new AttributeBonus(-2,1);
HealthAttribute healthAttribute = targetUnit.GetCharacterData().GetHealthAttribute();
healthAttribute.AddAttributeBonus(damageOutcome);
Debug.Log ("Normal attack skill to " +targetUnit+ ". Unit new HP is: " +targetUnit.GetCharacterData().GetHealthAttribute().GetModifiedValue());
this.PerformAnimation(sourceUnit, targetUnit);
}