public String useSkill(int skill, Characters enemy)
	{
		if (mana >= skillSet.getCost(skill))
		{
			
			int damage = roll(skillSet.getValue(skill));
			
			String message = skillSet.getDescription(skill);
			if (damage > 0)
			{
				message = message + " " + enemy.getName() + " suffers " + damage + " damage.";
			}
			else if (damage < 0)
			{
				message = message + " " + enemy.getName() + " is healed for " + -damage + ".";
			}
			enemy.receiveDamage(damage);
			mana = mana - skillSet.getCost(skill);
			
			if (enemy.getHP() <= 0)
			{
				enemy.setHP(0);
				enemy.die();
			}
			
			return message;
		}
		else
		{
			return null;
		}
	}