A Merciful Death
Death had been lonely when Thanos had first approached her, her angels were gone and she was swept up by his affections and efforts to win her heart, he didn't curse her.
He didn't hurt her until he did.
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When death first became aware she saw soft lights and her loving angels, they were few in numbers but guarded her and the souls under her care as a mother would her cubs.
Each angel glowed with power, an angel for each type of death.
The angel of painless deaths was one of the first to be slaughtered.
To mortals, all angels look the same.
To gods and souls, each one glows with its personality.
Soon more and more angels fell, sometimes they were trapped, some tricked, others tortured. More and more angels died and the few that remained sacrificed themselves to guard the dead and their mistress against vengeful beings. Beings who sought more power would try and eat angel hearts and make armors with the angels' feathers.
Death hadn't always been inevitable, she never could be until life was given meaning. Death gave life meaning and in turn, life gave death purpose and power, after all, what makes people chase their dreams is the knowledge they one day won't be able to.
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When death awoke she was made to guard the soul stone, the rest of the infinity stones were scattered throughout the cosmos, some heavily guarded, others hidden in plain sight. Death was alone without her angels even the other beings (none of them were strong enough to be gods, she scoffed, her angels held more power in their breath alone) Hades, Hela, all of the lesser beings of death respected her, loved her power, but never her. Not like her angels.
Death was completely alone, all angels lost when her last angel was born, her angel with a soul glowing in a soft kaleidoscope of colors. This angel was not made at her hand, she was made at the hand of mercy and justice and gifted to death, and death loved her. So she hid her.
She hid the vibrant soul from everyone and sent her precious angel to earth, she was a mercy to the chaotic world but no one knew it yet.
The angel was blessed and cursed by the same gift, she knew all the secrets learned in death but loved nonetheless she was the best and worst of the world wrapped into one. She was the angel of death - she wasn't a cruel death or a painless death.
She was a blessing in disguise, she gifted death to souls who suffered from no hope of a better future and pleaded to leave, to burn and salt the earth.
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And so this miraculous paradox of an angel was born to Howard and Maria Stark. Antonia 'Toni' Natasha Stark was born into the perfect hell.
Her father, when present, was a raging, abusive drunk and Maria had long lost her fighting spirit under heavy drunken fists.
As little Antonia grew she was 'kidnapped' many times, some times by people, other times that wasn't always the case. Antonia would often sneak out to see Death, Death never called her Antonia like her raging father or disappointed mother.
Death called her precious, called her trouble in a fond tone with a laugh, called her lux mea est in tenebris (my light in the darkness), and named her Azrael. She longed to stay with Death, but Death told her she needed to stay safe, and so she always went home, knowing that death would guard her.
The first time Antonia used her powers was to spare a mother and child more abuse when she was 4.
She was 13 before she used her powers again, on a Tiberius Stone when he tried to assault her (death and her honey bear were pissed when they found out).
Tiberius was the first time she used death as karma, she learned that using her power of justice on people like Tiberius wasn't satisfying and she would do it personally should she ever need to make someone suffer.
As Antonia grew older she gained a reputation as; genius, billionaire, philanthropist, futurist, playgirl, and merchant of death.
But in Afghanistan?
Antonia never used her powers, she never needed to.
They didn't deserve the mercy of a swift death.
They would SUFFER
just like they made the innocent SUFFER
just like they made Yinsen SUFFER.
She would burn them alive for what they did and then she blew them to kingdom come.