Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When this card inflicts battle damage to your opponent: You can Special Summon 1 Level 4 or lower "Atlantean" Sea Serpent-Type monster from your Deck, except "Atlantean Marksman". When this card is sent to the Graveyard to activate a WATER monster's effect: Target 1 Set card your opponent controls; destroy that target.
--海皇の狙撃兵
--Atlantean Marksman
local s,id=GetID()
function s.initial_effect(c)
	--Special summon
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetCode(EVENT_BATTLE_DAMAGE)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e1:SetCondition(s.spcon)
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
	--Destroy 1 card
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_DESTROY)
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_TO_GRAVE)
	e2:SetCondition(s.descon)
	e2:SetTarget(s.destg)
	e2:SetOperation(s.desop)
	c:RegisterEffect(e2)
end
s.listed_series={SET_ATLANTEAN}
s.listed_names={id}
function s.spcon(e,tp,eg,ep,ev,re,r,rp)
	return ep==1-tp
end
function s.spfilter(c,e,tp)
	return not c:IsCode(id) and c:IsLevelBelow(4) and c:IsSetCard(SET_ATLANTEAN) and c:IsRace(RACE_SEASERPENT)
		and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
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.spfilter,tp,LOCATION_DECK,0,1,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_DECK)
end
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.spfilter,tp,LOCATION_DECK,0,1,1,nil,e,tp)
	if #g>0 then
		Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)
	end
end
function s.descon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():IsReason(REASON_COST) and re:IsActivated() and re:IsMonsterEffect()
		and re:GetHandler():IsAttribute(ATTRIBUTE_WATER)
end
function s.desfilter(c)
	return c:IsFacedown()
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsOnField() and chkc:IsControler(1-tp) and s.desfilter(chkc) end
	if chk==0 then return true end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DESTROY)
	local g=Duel.SelectTarget(tp,s.desfilter,tp,0,LOCATION_ONFIELD,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,g,#g,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) and tc:IsFacedown() then
		Duel.Destroy(tc,REASON_EFFECT)
	end
end