Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Effect Monsters Once per turn: You can target 1 face-up monster this card points to and 1 face-up monster your opponent controls; the opponent's target loses ATK equal to the ATK of the target this monster points to, until the end of this turn.
--アンダークロックテイカー
--Underclock Taker
--
local s,id=GetID()
function s.initial_effect(c)
	--link summon
	Link.AddProcedure(c,aux.FilterBoolFunctionEx(Card.IsType,TYPE_EFFECT),2,2)
	c:EnableReviveLimit()
	--atkdown
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_ATKCHANGE)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetTarget(s.atktg)
	e1:SetOperation(s.atkop)
	c:RegisterEffect(e1)
end
function s.atkfilter(c,g)
	return c:IsFaceup() and c:GetAttack()>0 and g:IsContains(c)
end
function s.atktg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	local lg=e:GetHandler():GetLinkedGroup()
	if chkc then return false end
	if chk==0 then return Duel.IsExistingTarget(s.atkfilter,tp,LOCATION_MZONE,0,1,nil,lg)
		and Duel.IsExistingTarget(Card.IsFaceup,tp,0,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SELF)
	local g=Duel.SelectTarget(tp,s.atkfilter,tp,LOCATION_MZONE,0,1,1,nil,lg)
	e:SetLabelObject(g:GetFirst())
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_OPPO)
	Duel.SelectTarget(tp,Card.IsFaceup,tp,0,LOCATION_MZONE,1,1,nil)
end
function s.atkop(e,tp,eg,ep,ev,re,r,rp)
	local tc1=e:GetLabelObject()
	local g=Duel.GetChainInfo(0,CHAININFO_TARGET_CARDS)
	local tc2=g:GetFirst()
	if tc1==tc2 then tc2=g:GetNext() end
	if tc1:IsFaceup() and tc1:IsRelateToEffect(e) and tc2:IsFaceup() and tc2:IsRelateToEffect(e) then
		local atk=tc1:GetAttack()
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetValue(-atk)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		tc2:RegisterEffect(e1)
	end
end