A Maltusian ancestor of the Guardians of the Universe (founders of the Green lantern Corps), it is by experimenting with her new Glow abilities that she makes contact with the Dreaming and Dream. Dream falls in love with Killala, and the two start a whirlwind romance that consumes Dream's whole attention.
It is during a meeting of great Universal manifestations that Desire, Dream's sibling, starts to play and influence Killala who then falls in love with Sto-OA.
They are seen by Dream in an embrace. Killala comes to learn the truth that the beings that surround her are not mere aliens, but the raw living spirits of the Universe. Terrified of what she learns about Dream, she retreats through use of the Glow into the arms of Sto-Oa, and together they stay until her own light ends and is then embraced by Sto-OA for eternity.
Desire's manipulation of Killala and Sto-Oa ended whatever affection and friendship Dream had for his sibling.