Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Effect Monsters Gains 500 ATK for each monster this card points to. Cannot be destroyed by battle or your opponent's card effects, while this card points to a monster.
--コード・トーカー
--Code Talker
--Scripted by Eerie Code
local s,id=GetID()
function s.initial_effect(c)
	--link summon
	Link.AddProcedure(c,aux.FilterBoolFunctionEx(Card.IsType,TYPE_EFFECT),2,2)
	c:EnableReviveLimit()
	--atk
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_UPDATE_ATTACK)
	e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e1:SetRange(LOCATION_MZONE)
	e1:SetValue(s.atkval)
	c:RegisterEffect(e1)
	--indes
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_SINGLE)
	e2:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCode(EFFECT_INDESTRUCTABLE_BATTLE)
	e2:SetCondition(s.incon)
	e2:SetValue(1)
	c:RegisterEffect(e2)
	local e3=e2:Clone()
	e3:SetCode(EFFECT_INDESTRUCTABLE_EFFECT)
	e3:SetValue(s.inval)
	c:RegisterEffect(e3)
end
function s.atkval(e,c)
	return #(c:GetLinkedGroup():Filter(Card.IsMonster,nil))*500
end
function s.incon(e)
	return #(e:GetHandler():GetLinkedGroup():Filter(Card.IsMonster,nil))>0
end
function s.inval(e,re,tp)
	return tp~=e:GetHandlerPlayer()
end