For my character, N'vui and the N’juitsalyi (should they be relevant), are not and know they are not truly immortal. Their long lives are not attributed to any inherent immortality, but is the product of having a surplus of all the energy remaining in living beings once they had passed. Along with that their own skill to avoid or circumvent lethal damage. Personal protection and a continuous long lasting spell. On another subject, I feel Candice and N'vui would probably get along.