Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If you control no monsters, you can Special Summon this card (from your hand) by discarding 1 Cyberse monster. All monsters your opponent controls lose 500 ATK.
--スレッショルド・ボーグ
--Threshold Borg
--Scripted by AlphaKretin
local s,id=GetID()
function s.initial_effect(c)
	--special summon
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_SPSUMMON_PROC)
	e1:SetProperty(EFFECT_FLAG_UNCOPYABLE)
	e1:SetRange(LOCATION_HAND)
	e1:SetCondition(s.spcon)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
	--reduce atk
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetRange(LOCATION_MZONE)
	e2:SetTargetRange(0,LOCATION_MZONE)
	e2:SetCode(EFFECT_UPDATE_ATTACK)
	e2:SetValue(-500)
	c:RegisterEffect(e2)
end
function s.spcon(e,c)
	if c==nil then return true end
	return Duel.GetFieldGroupCount(e:GetHandlerPlayer(),LOCATION_MZONE,0)==0 and
		Duel.IsExistingMatchingCard(Card.IsRace,c:GetControler(),LOCATION_HAND,0,1,c,RACE_CYBERSE)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp,c)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DISCARD)
	local g=Duel.SelectMatchingCard(tp,Card.IsRace,tp,LOCATION_HAND,0,1,1,c,RACE_CYBERSE)
	Duel.SendtoGrave(g,REASON_DISCARD|REASON_COST)
end