Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Add 1 "Junk Synchron", and 1 monster that mentions "Junk Warrior" or "Stardust Dragon", from your Deck to your hand, then discard 1 card. You can banish this card from your GY, then target 1 Synchro Monster you control; decrease its Level by 1, then, during your Main Phase this turn, you can Normal Summon 1 "Synchron" monster, in addition to your Normal Summon/Set (you can only gain this effect once per turn). You can only activate 1 "Synchro Fellows" per turn.
--シンクロ・フェローズ
--Synchro Fellows
--scripted by pyrQ
local s,id=GetID()
function s.initial_effect(c)
	--Add 1 "Junk Synchron", and 1 monster that mentions "Junk Warrior" or "Stardust Dragon", from your Deck to your hand, then discard 1 card
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_TOHAND+CATEGORY_SEARCH+CATEGORY_HANDES)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_OATH)
	e1:SetTarget(s.thtg)
	e1:SetOperation(s.thop)
	c:RegisterEffect(e1)
	--Decrease the Level of 1 Synchro Monster you control by 1
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_LVCHANGE)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetRange(LOCATION_GRAVE)
	e2:SetCondition(function(e,tp) return Duel.IsPlayerCanAdditionalSummon(tp) and not Duel.HasFlagEffect(tp,id) end)
	e2:SetCost(Cost.SelfBanish)
	e2:SetTarget(s.lvtg)
	e2:SetOperation(s.lvop)
	c:RegisterEffect(e2)
end
s.listed_names={CARD_JUNK_SYNCHRON,CARD_JUNK_WARRIOR,CARD_STARDUST_DRAGON}
s.listed_series={SET_SYNCHRON}
function s.thfilter(c)
	return (c:IsCode(CARD_JUNK_SYNCHRON) or (c:IsMonster() and c:ListsCode(CARD_JUNK_WARRIOR,CARD_STARDUST_DRAGON))) and c:IsAbleToHand()
end
function s.rescon(sg,e,tp,mg)
	return sg:IsExists(Card.IsCode,1,nil,CARD_JUNK_SYNCHRON) and sg:IsExists(Card.ListsCode,1,nil,CARD_JUNK_WARRIOR,CARD_STARDUST_DRAGON)
end
function s.thtg(e,tp,eg,ep,ev,re,r,rp,chk)
	local g=Duel.GetMatchingGroup(s.thfilter,tp,LOCATION_DECK,0,nil)
	if chk==0 then return aux.SelectUnselectGroup(g,e,tp,2,2,s.rescon,0) end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,nil,2,tp,LOCATION_DECK)
	Duel.SetOperationInfo(0,CATEGORY_HANDES,nil,0,tp,1)
end
function s.thop(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetMatchingGroup(s.thfilter,tp,LOCATION_DECK,0,nil)
	if #g==0 then return end
	local sg=aux.SelectUnselectGroup(g,e,tp,2,2,s.rescon,1,tp,HINTMSG_ATOHAND)
	if #sg>0 and Duel.SendtoHand(sg,nil,REASON_EFFECT)>0 then
		Duel.ConfirmCards(1-tp,sg)
		Duel.ShuffleHand(tp)
		Duel.BreakEffect()
		Duel.DiscardHand(tp,nil,1,1,REASON_EFFECT|REASON_DISCARD)
	end
end
function s.lvfilter(c)
	return c:IsSynchroMonster() and c:IsLevelAbove(2) and c:IsFaceup()
end
function s.lvtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(tp) and s.lvfilter(chkc) end
	if chk==0 then return Duel.IsPlayerCanSummon(tp)
		and Duel.IsExistingTarget(s.lvfilter,tp,LOCATION_MZONE,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TARGET)
	local g=Duel.SelectTarget(tp,s.lvfilter,tp,LOCATION_MZONE,0,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_LVCHANGE,g,1,tp,1)
end
function s.lvop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) and tc:IsFaceup() and tc:IsLevelAbove(2) and not tc:IsImmuneToEffect(e) then
		--Decrease its Level by 1
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
		e1:SetCode(EFFECT_UPDATE_LEVEL)
		e1:SetValue(-1)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD)
		tc:RegisterEffect(e1)
		Duel.BreakEffect()
		aux.RegisterClientHint(c,nil,tp,1,0,aux.Stringid(id,2))
		Duel.RegisterFlagEffect(tp,id,RESET_PHASE|PHASE_END,0,1)
		--You can Normal Summon 1 "Synchron" monster during your Main Phase this turn, in addition to your Normal Summon/Set (you can only gain this effect once per turn)
		local e2=Effect.CreateEffect(c)
		e2:SetType(EFFECT_TYPE_FIELD)
		e2:SetCode(EFFECT_EXTRA_SUMMON_COUNT)
		e2:SetTargetRange(LOCATION_HAND|LOCATION_MZONE,0)
		e2:SetTarget(aux.TargetBoolFunction(Card.IsSetCard,SET_SYNCHRON))
		e2:SetReset(RESET_PHASE|PHASE_END)
		Duel.RegisterEffect(e2,tp)
	end
end