Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 4 monsters Once per turn: You can detach 1 Xyz Material from this card, then target 1 Defense Position monster on the field; change it to face-up Attack Position, and if you do, it loses 600 ATK.
--フォトン・バタフライ・アサシン
--Photon Papilloperative
local s,id=GetID()
function s.initial_effect(c)
	--xyz summon
	Xyz.AddProcedure(c,nil,4,2)
	c:EnableReviveLimit()
	--pos&atk
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_POSITION+CATEGORY_ATKCHANGE)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetCountLimit(1)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCost(Cost.DetachFromSelf(1))
	e1:SetTarget(s.postg)
	e1:SetOperation(s.posop)
	c:RegisterEffect(e1)
end
function s.postg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsDefensePos() end
	if chk==0 then return Duel.IsExistingTarget(Card.IsDefensePos,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DEFENSE)
	local g=Duel.SelectTarget(tp,Card.IsDefensePos,tp,LOCATION_MZONE,LOCATION_MZONE,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_POSITION,g,#g,0,0)
end
function s.posop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsDefensePos() and tc:IsRelateToEffect(e) then
		Duel.ChangePosition(tc,POS_FACEUP_ATTACK)
		if tc:IsPosition(POS_FACEUP_ATTACK) then
			local e1=Effect.CreateEffect(e:GetHandler())
			e1:SetType(EFFECT_TYPE_SINGLE)
			e1:SetCode(EFFECT_UPDATE_ATTACK)
			e1:SetValue(-600)
			e1:SetReset(RESET_EVENT|RESETS_STANDARD)
			tc:RegisterEffect(e1)
		end
	end
end