Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
3 Level 7 monsters Once per turn, you can also Xyz Summon "Poseidra Abyss, the Atlantean Dragon Lord" by using 1 "Atlantean" or "Mermail" Xyz Monster you control. (Transfer its materials to this card.) Once per turn: You can detach 2 materials from this card, then send 1 WATER monster from your hand or Deck to the GY; return up to 3 cards your opponent controls to the hand. If this Xyz Summoned card is sent to the GY: You can discard 1 card to the GY; Special Summon 3 Level 3 or lower Fish, Sea Serpent, and/or Aqua monsters from your hand and/or GY.
--海皇龍神 ポセイドラ・アビス
--Poseidra Abyss, the Atlantean Dragon Lord
--scripted by Naim
local s,id=GetID()
function s.initial_effect(c)
	c:EnableReviveLimit()
	--Xyz Summon procedure: 3 Level 7 monsters OR 1 "Atlantean" or "Mermail" Xyz Monster you control
	Xyz.AddProcedure(c,nil,7,3,s.ovfilter,aux.Stringid(id,0),3,s.xyzop)
	--Return up to 3 cards your opponent controls to the hand
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,1))
	e1:SetCategory(CATEGORY_TOHAND)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetCost(Cost.AND(Cost.DetachFromSelf(2),s.rthcost))
	e1:SetTarget(s.rthtg)
	e1:SetOperation(s.rthop)
	c:RegisterEffect(e1)
	--Special Summon 3 Level 3 or lower Fish, Sea Serpent, and/or Aqua monsters from your hand and/or GY.
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,2))
	e2:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e2:SetProperty(EFFECT_FLAG_DELAY)
	e2:SetCode(EVENT_TO_GRAVE)
	e2:SetCondition(s.spcon)
	e2:SetCost(s.spcost)
	e2:SetTarget(s.sptg)
	e2:SetOperation(s.spop)
	c:RegisterEffect(e2)
end
s.listed_series={SET_ATLANTEAN,SET_MERMAIL}
s.listed_names={id}
function s.ovfilter(c,tp,lc)
	return c:IsSetCard(s.listed_series,lc,SUMMON_TYPE_XYZ,tp) and c:IsType(TYPE_XYZ,lc,SUMMON_TYPE_XYZ,tp) and c:IsFaceup()
end
function s.xyzop(e,tp,chk)
	if chk==0 then return not Duel.HasFlagEffect(tp,id) end
	return Duel.RegisterFlagEffect(tp,id,RESET_PHASE|PHASE_END,EFFECT_FLAG_OATH,1)
end
function s.rthcostfilter(c)
	return c:IsAttribute(ATTRIBUTE_WATER) and c:IsAbleToGraveAsCost()
end
function s.rthcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.rthcostfilter,tp,LOCATION_HAND|LOCATION_DECK,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TOGRAVE)
	local g=Duel.SelectMatchingCard(tp,s.rthcostfilter,tp,LOCATION_HAND|LOCATION_DECK,0,1,1,nil)
	Duel.SendtoGrave(g,REASON_COST)
end
function s.rthtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(Card.IsAbleToHand,tp,0,LOCATION_ONFIELD,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,nil,1,1-tp,LOCATION_ONFIELD)
end
function s.rthop(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_RTOHAND)
	local g=Duel.SelectMatchingCard(tp,Card.IsAbleToHand,tp,0,LOCATION_ONFIELD,1,3,nil)
	if #g>0 then
		Duel.HintSelection(g)
		Duel.SendtoHand(g,nil,REASON_EFFECT)
	end
end
function s.spcon(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	return c:IsPreviousLocation(LOCATION_MZONE) and c:IsXyzSummoned()
end
function s.spcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(aux.AND(Card.IsDiscardable,Card.IsAbleToGraveAsCost),tp,LOCATION_HAND,0,1,nil) end
	Duel.DiscardHand(tp,aux.AND(Card.IsDiscardable,Card.IsAbleToGraveAsCost),1,1,REASON_COST|REASON_DISCARD)
end
function s.spfilter(c,e,tp)
	return c:IsLevelBelow(3) and c:IsRace(RACE_FISH|RACE_SEASERPENT|RACE_AQUA) 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 not Duel.IsPlayerAffectedByEffect(tp,CARD_BLUEEYES_SPIRIT)
		and Duel.GetLocationCount(tp,LOCATION_MZONE)>=3
		and Duel.IsExistingMatchingCard(s.spfilter,tp,LOCATION_HAND|LOCATION_GRAVE,0,3,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_HAND|LOCATION_GRAVE)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetLocationCount(tp,LOCATION_MZONE)<3 or Duel.IsPlayerAffectedByEffect(tp,CARD_BLUEEYES_SPIRIT) then return end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectMatchingCard(tp,aux.NecroValleyFilter(s.spfilter),tp,LOCATION_HAND|LOCATION_GRAVE,0,3,3,nil,e,tp)
	if #g==3 then
		Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)
	end
end