Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If all monsters your opponent controls are in Defense Position, this card can attack your opponent directly.
--闇の住人シャドウキラー
--Shadowslayer
local s,id=GetID()
function s.initial_effect(c)
	--direct attack
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_DIRECT_ATTACK)
	e1:SetCondition(s.con)
	c:RegisterEffect(e1)
end
function s.con(e)
	return not Duel.IsExistingMatchingCard(Card.IsAttackPos,e:GetHandler():GetControler(),0,LOCATION_MZONE,1,nil)
end