Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Discard 1 card; all monsters your opponent currently controls lose 500 ATK/DEF until the end of this turn.
--老化の呪い
--Curse of Aging
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_ATKCHANGE)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetProperty(EFFECT_FLAG_DAMAGE_STEP)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetHintTiming(TIMING_DAMAGE_STEP)
	e1:SetCondition(aux.StatChangeDamageStepCondition)
	e1:SetCost(s.cost)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
function s.cost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(Card.IsDiscardable,tp,LOCATION_HAND,0,1,e:GetHandler()) end
	Duel.DiscardHand(tp,Card.IsDiscardable,1,1,REASON_COST|REASON_DISCARD)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(Card.IsFaceup,tp,0,LOCATION_MZONE,1,nil) end
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetMatchingGroup(Card.IsFaceup,tp,0,LOCATION_MZONE,nil)
	if #g>0 then
		for tc in g:Iter() do
			local e1=Effect.CreateEffect(e:GetHandler())
			e1:SetType(EFFECT_TYPE_SINGLE)
			e1:SetCode(EFFECT_UPDATE_ATTACK)
			e1:SetReset(RESETS_STANDARD_PHASE_END)
			e1:SetValue(-500)
			tc:RegisterEffect(e1)
			local e2=e1:Clone()
			e2:SetCode(EFFECT_UPDATE_DEFENSE)
			tc:RegisterEffect(e2)
		end
	end
end