Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Target 1 "Mermail" monster you control; it gains 1000 ATK until the End Phase. When this Set card is sent to the Graveyard: Target 1 monster your opponent controls; send that target to the Graveyard.
--アビスコーン
--Abyss-scorn
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_ATKCHANGE)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET+EFFECT_FLAG_DAMAGE_STEP)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetHintTiming(TIMING_DAMAGE_STEP)
	e1:SetCondition(aux.StatChangeDamageStepCondition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	--
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_TO_GRAVE)
	e2:SetCondition(s.tgcon)
	e2:SetTarget(s.tgtg)
	e2:SetOperation(s.tgop)
	c:RegisterEffect(e2)
end
s.listed_series={SET_MERMAIL}
function s.filter(c)
	return c:IsFaceup() and c:IsSetCard(SET_MERMAIL)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(tp) and s.filter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.filter,tp,LOCATION_MZONE,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	Duel.SelectTarget(tp,s.filter,tp,LOCATION_MZONE,0,1,1,nil)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) and tc:IsFaceup() then
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		e1:SetValue(1000)
		tc:RegisterEffect(e1)
	end
end
function s.tgcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():IsPreviousLocation(LOCATION_ONFIELD) and e:GetHandler():IsPreviousPosition(POS_FACEDOWN)
end
function s.tgtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(1-tp) end
	if chk==0 then return true end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TOGRAVE)
	local g=Duel.SelectTarget(tp,nil,tp,0,LOCATION_MZONE,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_TOGRAVE,g,#g,0,0)
end
function s.tgop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) then
		Duel.SendtoGrave(tc,REASON_EFFECT)
	end
end