Bud-Clare writes...

"ALONE: The Demona Contest Answer"

Consciously, Demona chose the password "alone" because she believed that she alone understood that the humans must be destroyed at all costs. She was forced to bear the burden of her crusade against humanity alone, since Goliath and the others were "too blind" to see that she was right.

I would think that her subconscious appreciated the irony of her choice. If Demona had succeeded, she would have truly been alone… permanently. Her murder of the clan would likely have placed her beyond all hope of redemption, and Angela would have been killed during the attack on Avalon.