Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Target 1 Level 7 or 8 Dragon monster in your GY; Special Summon it. If a Dragon monster(s) you control would be destroyed by battle or card effect, you can banish this card from your GY instead.
--復活の福音
--Return of the Dragon Lords
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	--destroy replace
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_CONTINUOUS)
	e2:SetCode(EFFECT_DESTROY_REPLACE)
	e2:SetRange(LOCATION_GRAVE)
	e2:SetTarget(s.reptg)
	e2:SetValue(s.repval)
	e2:SetOperation(s.repop)
	c:RegisterEffect(e2)
end
function s.filter(c,e,tp)
	return c:IsRace(RACE_DRAGON) and (c:GetLevel()==7 or c:GetLevel()==8) and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsControler(tp) and chkc:IsLocation(LOCATION_GRAVE) and s.filter(chkc,e,tp) end
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingTarget(s.filter,tp,LOCATION_GRAVE,0,1,nil,e,tp) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectTarget(tp,s.filter,tp,LOCATION_GRAVE,0,1,1,nil,e,tp)
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,g,1,0,0)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) then
		Duel.SpecialSummon(tc,0,tp,tp,false,false,POS_FACEUP)
	end
end
function s.repfilter(c,tp)
	return c:IsFaceup() and c:IsRace(RACE_DRAGON) and c:IsLocation(LOCATION_MZONE) and c:IsControler(tp) 
		and not c:IsReason(REASON_REPLACE) and c:IsReason(REASON_EFFECT|REASON_BATTLE)
end
function s.reptg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return e:GetHandler():IsAbleToRemove() and eg:IsExists(s.repfilter,1,nil,tp) end
	return Duel.SelectEffectYesNo(tp,e:GetHandler(),96)
end
function s.repval(e,c)
	return s.repfilter(c,e:GetHandlerPlayer())
end
function s.repop(e,tp,eg,ep,ev,re,r,rp)
	Duel.Remove(e:GetHandler(),POS_FACEUP,REASON_EFFECT)
end