Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Each time an opponent's monster declares an attack, you gain 500 LP. If this card is Normal or Special Summoned and you control no other monsters: You can Special Summon 1 "Lil-la" monster from your hand or Deck. You can only use this effect of "Live☆Twin Ki-sikil" once per turn.
--Ｌｉｖｅ☆Ｔｗｉｎ キスキル
--Live☆Twin Ki-sikil
--Logical Nonsense
--Substitute ID
local s,id=GetID()
function s.initial_effect(c)
	--If normal summoned, special summon 1 "Lilla" monster
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e1:SetProperty(EFFECT_FLAG_DELAY+EFFECT_FLAG_DAMAGE_STEP)
	e1:SetCode(EVENT_SUMMON_SUCCESS)
	e1:SetCountLimit(1,id)
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
	--Same as above but if special summoned
	local e2=e1:Clone()
	e2:SetCode(EVENT_SPSUMMON_SUCCESS)
	c:RegisterEffect(e2)
	--Each time opponent declares an attack, gain 500 LP
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_CONTINUOUS)
	e3:SetCode(EVENT_ATTACK_ANNOUNCE)
	e3:SetRange(LOCATION_MZONE)
	e3:SetOperation(s.lpop)
	c:RegisterEffect(e3)
end
	--Lists "Lilla" archetype
s.listed_series={SET_LIL_LA}
	--Specifically lists itself
s.listed_names={id}
	--Check for "Lilla" monster
function s.filter(c,e,tp)
	return c:IsSetCard(SET_LIL_LA) and c:IsCanBeSpecialSummoned(e,0,tp,false,false,POS_FACEUP)
end
	--Activation legality
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_DECK|LOCATION_HAND,0,1,nil,e,tp)
		and not Duel.IsExistingMatchingCard(nil,tp,LOCATION_MZONE,0,1,e:GetHandler()) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_DECK|LOCATION_HAND)
end
	--Special summon 1 "Lilla" monster from hand/deck
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetLocationCount(tp,LOCATION_MZONE)<=0 then return end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_DECK|LOCATION_HAND,0,1,1,nil,e,tp)
	if #g>0 then
		Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)
	end
end
	--Each time opponent declares an attack, gain 500 LP
function s.lpop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetAttacker():IsControler(1-tp) then
		Duel.Recover(tp,500,REASON_EFFECT)
	end
end