Since you insist I'll tell it to you.
First of all the owner is only invincible inside the bank of universe but when outside the owner is only as strong as his cultivation so when a person stronger than the owner borrowed a godly item they can run away with it caz the owner can't get it back since his weaker than the person.
[ Quick explanation : the bank of universe is an independent small world and when a person wants something from the bank of universe they get an invitation and teleported to the bank of universe and after the transaction they get teleported back to where they originally was wherever they are in the 9 worlds and 10 lands ]
