Reliant Immortality.
Existences with this type of immortality gain the benefits of one or more other kinds of Immortality as long as a certain being, object, place, or concept provides those benefits, losing them if it no longer does.
In Artemisia's case, that 'object' was the entire 'Planet Aidos'.
"No fucking way you should be able to link a whole planet to become your lifeli—!"
Evan couldn't bring himself to believe what he'd just heard, but mid-sentence, he froze, eyes widening as he remembered Artemisia's words about Valmone's indulgence of her.
"Wait...the universe let you do that?!"
Because of that indulgence, Artemisia could perform the absurd act of tying her life to a Prime World.
"It's a fair deal. Planets eventually die, even if it takes billions of years. I, however, possess an eternal lifespan that would outlast any planet. So I traded with Aidos. It would share my eternal lifespan, and its continued existence would ensure mine could never end."
