Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Target face-up "Gladiator Beast" monster you control gains 500 ATK until the End Phase. While this card is in your Graveyard, you can return 2 "Gladiator Beast" cards from your Graveyard to the Deck to return this card to your hand.
--剣闘獣の底力
--Indomitable Gladiator Beast
local s,id=GetID()
function s.initial_effect(c)
	--Make 1 "Gladiator Beast" monster you control gain 500 ATK until the end of this turn
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	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:SetCondition(aux.StatChangeDamageStepCondition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	e1:SetHintTiming(TIMING_DAMAGE_STEP)
	c:RegisterEffect(e1)
	--Add this card to your hand
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_TOHAND)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetRange(LOCATION_GRAVE)
	e2:SetCost(s.rthcost)
	e2:SetTarget(s.rthtg)
	e2:SetOperation(s.rthop)
	c:RegisterEffect(e2)
end
s.listed_series={SET_GLADIATOR_BEAST}
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 chkc:IsSetCard(SET_GLADIATOR_BEAST) and chkc:IsFaceup() end
	if chk==0 then return Duel.IsExistingTarget(aux.FaceupFilter(Card.IsSetCard,SET_GLADIATOR_BEAST),tp,LOCATION_MZONE,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATKDEF)
	Duel.SelectTarget(tp,aux.FaceupFilter(Card.IsSetCard,SET_GLADIATOR_BEAST),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() and tc:IsControler(tp) and tc:IsSetCard(SET_GLADIATOR_BEAST) then
		--It gains 500 ATK until the end of this turn
		tc:UpdateAttack(500,RESETS_STANDARD_PHASE_END,e:GetHandler())
	end
end
function s.rthcostfilter(c)
	return c:IsSetCard(SET_GLADIATOR_BEAST) and c:IsAbleToDeckAsCost()
end
function s.rthcost(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then return Duel.IsExistingMatchingCard(s.rthcostfilter,tp,LOCATION_GRAVE,0,2,c) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TODECK)
	local g=Duel.SelectMatchingCard(tp,s.rthcostfilter,tp,LOCATION_GRAVE,0,2,2,c)
	Duel.HintSelection(g)
	Duel.SendtoDeck(g,nil,SEQ_DECKSHUFFLE,REASON_COST)
end
function s.rthtg(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then return c:IsAbleToHand() end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,c,1,tp,0)
end
function s.rthop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) then
		Duel.SendtoHand(c,nil,REASON_EFFECT)
	end
end