Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
You can Normal Summon Level 7 monsters without Tributing. During your Main Phase: You can Special Summon 1 of your non-Xyz "Kashtira" monsters that is banished or in your GY. If your opponent activates a Spell Card or effect, and you control a "Kashtira" monster: You can target 3 cards in your opponent's GY; banish them, face-down. You can only use each effect of "Kashtira Birth" once per turn.
--クシャトリラ・バース
--Kashtira Birth
--Scripted by Eerie Code
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--Level 7 monsters can be summoned without Tributing
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_SUMMON_PROC)
	e2:SetRange(LOCATION_SZONE)
	e2:SetTargetRange(LOCATION_HAND,0)
	e2:SetCountLimit(1,{id,0})
	e2:SetCondition(s.ntcon)
	e2:SetTarget(aux.FieldSummonProcTg(s.nttg))
	c:RegisterEffect(e2)
	--Special Summon 1 non-Xyz "Kashtira" monster
	local e3=Effect.CreateEffect(c)
	e3:SetDescription(aux.Stringid(id,1))
	e3:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e3:SetType(EFFECT_TYPE_IGNITION)
	e3:SetRange(LOCATION_SZONE)
	e3:SetCountLimit(1,{id,1})
	e3:SetTarget(s.sptg)
	e3:SetOperation(s.spop)
	c:RegisterEffect(e3)
	--Banish 3 cards from the GY
	local e4=Effect.CreateEffect(c)
	e4:SetDescription(aux.Stringid(id,2))
	e4:SetCategory(CATEGORY_REMOVE)
	e4:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e4:SetProperty(EFFECT_FLAG_CARD_TARGET+EFFECT_FLAG_DELAY)
	e4:SetCode(EVENT_CHAIN_SOLVED)
	e4:SetRange(LOCATION_SZONE)
	e4:SetCountLimit(1,{id,2})
	e4:SetCondition(s.rmcon)
	e4:SetTarget(s.rmtg)
	e4:SetOperation(s.rmop)
	c:RegisterEffect(e4)
end
s.listed_series={SET_KASHTIRA}
function s.ntcon(e,c,minc)
	if c==nil then return true end
	return minc==0 and Duel.GetLocationCount(c:GetControler(),LOCATION_MZONE)>0
end
function s.nttg(e,c)
	return c:IsLevel(7)
end
function s.spfilter(c,e,tp)
	return c:IsFaceup() and c:IsSetCard(SET_KASHTIRA) and not c:IsType(TYPE_XYZ)
		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_GRAVE|LOCATION_REMOVED,0,1,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_GRAVE|LOCATION_REMOVED)
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,aux.NecroValleyFilter(s.spfilter),tp,LOCATION_GRAVE|LOCATION_REMOVED,0,1,1,nil,e,tp)
	if #g>0 then
		Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)
	end
end
function s.rmcon(e,tp,eg,ep,ev,re,r,rp)
	return rp==1-tp and re:IsSpellEffect()
end
function s.rmfilter(c,tp)
	return c:IsAbleToRemove(tp,POS_FACEDOWN) and aux.SpElimFilter(c)
end
function s.rmtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE|LOCATION_GRAVE) and chkc:IsControler(1-tp) and s.rmfilter(chkc,tp) end
	if chk==0 then return Duel.IsExistingMatchingCard(aux.FaceupFilter(Card.IsSetCard,SET_KASHTIRA),tp,LOCATION_MZONE,0,1,nil)
		and Duel.IsExistingTarget(s.rmfilter,tp,0,LOCATION_MZONE|LOCATION_GRAVE,3,nil,tp) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_REMOVE)
	local g=Duel.SelectTarget(tp,s.rmfilter,tp,0,LOCATION_MZONE|LOCATION_GRAVE,3,3,nil,tp)
	Duel.SetOperationInfo(0,CATEGORY_REMOVE,g,#g,0,0)
end
function s.rmop(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetTargetCards(e)
	if #g>0 then
		Duel.Remove(g,POS_FACEDOWN,REASON_EFFECT)
	end
end