The Darkness

The Darkness, often called by her other name Amara, is a supremely powerful primordial entity who has existed since before the beginning of time, predating both God and Death, who were of similar age. Sometime later, after her brother God came into being, he created the Archangels to fight a terrible war against her. Through the combined power of God and the Archangels, God sealed her away, not wanting to kill her, by using the Mark of Cain as both a lock and key. God revealed that he chose not to kill her in her weakened state as she needed to exist with himself so reality wouldn't be destroyed. Whilst the Archangels battled her and thus knew of her existence, she is so ancient and mysterious that the Demons and even the Angels, except for Metatron and Tsubaki, didn't believe she existed or was locked away. However, Metatron knew about her and who she was, as he was God's scribe, with Tsubaki knowing due to having met her before.

Personality
Due to her imprisonment, Amara had no knowledge or understanding of how God's universe worked. However, after feeding on various souls and studying important points in human history, she finally came to the conclusion that her brother had "screwed up" when he made the world, saying that Heaven, Hell, good, evil, and even people seemed unimportant. When she was first released, she intended to remake the world as she saw fit: a world where nobody had to suffer, and instead lived blissfully for eternity. However, she also wanted to destroy everything that her brother had created to make him suffer.

In her younger forms, she was very impatient and easily became upset if she wasn't given what she wanted immediately. As an adult, she said she deserved to have - and be - everything. As she was the beginning, so too would she be the end.

Both Lucifer and Amara alluded to their long-term plans, but with different connotations. Lucifer stated that, unlike God, whom he describes as "a master strategist," Amara is prone to tantrums and baldness of experience.

From the moment of her release, Amara became infatuated by Tsubaki, as she'd been the one to release her (from her point of view). She said it was destiny that she had been released, and that they would one day become one.

Eventually, it turns out that Amara was only interested in Tsubaki because she did not want to be alone after taking revenge on God. She has even stated that she has loved God more than he could ever imagine. After getting her revenge, Amara began to lament her actions as, despite everything God did to her, she still loved her brother.

As God and his creation began to die, Amara really began to see beauty at all and admitted that along with the real reason for her actions: jealousy. Amara had been jealous of God for needing something else; something that was not her, but after he created life and made her consumed by rage. After releasing the jealousy and anger, Amara finally had what she really wanted all the time: her brother back is what made her happy.

Despite her beliefs, Amara showed the ability to admit that she is wrong and to make amends as she did with God. It seemed she had built her vengeance so much that Amara never considered what would happen when she succeeded. After being confronted with the reality of what she did, she understood her mistake.