Mary was right when she said Lilith was jealous of Shannon.

She'll never admit it aloud, but it has nothing to do with the Halo. Lilith knows that now the way she knows this demonic corruption has become part of her.

Her jealousy comes from a deeper place in her psyche, a place that once caused Beatrice to cry herself to sleep at night while Lilith comforted her, and even now brings Mary's rage to the surface, ready to be unleashed.

Yet where it lives inside her has nothing to do with the why of it, because the why is such a simple thing that Lilith's surprised it took herself so long to realise the truth.

Lilith was jealous of Shannon for being with Mary. Mary! Beautiful, wicked, humorous Mary, always by Shannon's side while Lilith stood in her shadow.

All those years she spent training, fighting to be noticed, all but screaming 'look at me', while Mary's gaze never left Shannon's holy visage. And yes, it should've been her who received the Halo when Shannon died, because then Mary might have looked at Lilith and finally seen her.

Instead, she's been condemned to live in another's shadow yet again.