I'm pretty sure that Aura and Mare are one of the few, if not only, beings in Nazarick with a definite lifespan and age. Given this, how will Ainz treat Aura and Mare if they get too old? Is there a way to slow/stop their aging at a certain age, maybe through a Fallen Seed or some other item? Aureole is an immortal human, so is there a way for Ainz in the New World to make them immortal elves?