Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Cannot be Normal Summoned/Set. Must be Special Summoned with the effect of a "Drytron" card. You can Tribute 1 other "Drytron" monster, or 1 Ritual Monster, from your hand or field; Special Summon this card from your hand or GY in Defense Position, then you can Special Summon 1 "Drytron" monster with 2000 ATK from your GY, except "Drytron Gamma Eltanin". You cannot Special Summon monsters, except monsters that cannot be Normal Summoned/Set, the turn you activate this effect. You can only use this effect of "Drytron Gamma Eltanin" once per turn.
--竜輝巧－エルγ
--Drytron Gamma Eltanin
--scripted by pyrQ
local s,id=GetID()
function s.initial_effect(c)
	--Cannot be Normal Summoned/Set
	c:EnableUnsummonable()
	--Special Summon condition
	local e1=Effect.CreateEffect(c)
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_SPSUMMON_CONDITION)
	e1:SetValue(s.spconlimit)
	c:RegisterEffect(e1)
	--Special Summon this card
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetRange(LOCATION_HAND|LOCATION_GRAVE)
	e2:SetCountLimit(1,id)
	e2:SetCost(Drytron.TributeCost)
	e2:SetTarget(s.sptg)
	e2:SetOperation(s.spop)
	c:RegisterEffect(e2)
	Duel.AddCustomActivityCounter(id,ACTIVITY_SPSUMMON,s.sumfilter)
end
s.listed_series={SET_DRYTRON}
s.listed_names={id}
function s.spconlimit(e,se,sp,st)
	return se:IsHasType(EFFECT_TYPE_ACTIONS) and se:GetHandler():IsSetCard(SET_DRYTRON)
end
function s.sumfilter(c)
	return not c:IsSummonableCard()
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then return c:IsCanBeSpecialSummoned(e,0,tp,false,false,POS_FACEUP_DEFENSE) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,c,1,0,c:GetLocation())
	Duel.SetPossibleOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_GRAVE)
end
function s.spfilter(c,e,tp)
	return c:IsSetCard(SET_DRYTRON) and c:IsMonster() and c:IsAttack(2000)
		and c:IsCanBeSpecialSummoned(e,0,tp,false,false) and not c:IsCode(id)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) and Duel.SpecialSummon(c,0,tp,tp,false,false,POS_FACEUP_DEFENSE)>0 then
		local g=Duel.GetMatchingGroup(aux.NecroValleyFilter(s.spfilter),tp,LOCATION_GRAVE,0,nil,e,tp)
		if #g>0 and Duel.GetLocationCount(tp,LOCATION_MZONE)>0 and Duel.SelectYesNo(tp,aux.Stringid(id,2)) then
			Duel.BreakEffect()
			Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
			local sg=g:Select(tp,1,1,nil)
			Duel.SpecialSummon(sg,0,tp,tp,false,false,POS_FACEUP)
		end
	end
end