if any sin could be counted against will, it’d be his willingness to put those he loves before anyone else- himself, God, other angels. it’s that love that caused him to fall in the first place. he was one of the watchers originally, sent amoungst humanity to watch and protect. and he fell in love.
he grew close to a human woman whom fallen deeply and hopelessly in love with her. taking on a human form of his own and taking her as his wife. they were happy, having a few children too– which was part of his downfall– bringing nephilim into the world, no matter how well they were loved.
heaven broke down his door when the order went out to destroy any and all nephilim on earth, dragging will kicking and screaming and helpless while his children- and his wife in her attempt to save their children- were butchered in front of him after his refusal to commit the deed instead. for refusing to be the good soldier he was created to be as well as the sin of those nephilim existing in the first place.
his punishment, aside from the senseless murder of his wife and children, was to have his Grace striped from him and cast down from heaven to live and die again and again, always a soldier too, until the lesson sunk in to follow orders. to do what he was told. the cycle doomed to repeat itself until He intervened or someone else took pity on the fallen seraph, wittingly or otherwise.
he fell screaming from heaven; cursing the name of those involved– including Him.
will has very few memories of his life before this turn around the cycle of humanity; aside from nightmares that haunt him of disjointed memories as an angel, and a few scattered memories of some of his past lives, he doesn’t really remember. and doesn’t want too from what he does remember.
truth be told, he doesn’t even know how he got his Grace back, just the event of it coming crashing into him; burning him from the inside out, like he’d been submerged into the arctic, from his very core. and light, so much light that blinded him and than having to pull himself back together– quite literally since his Grace technically burned his body away with it’s intensity, which is why some minor things no longer exist that did when he was human, like small scars and signs of the shit he’d gone through as a human, things he’d done to himself over the years and wear and tear of life in general.
he does remember getting dragged kicking and screaming into the silver city again when he regained his Grace, breaking free from and even managing to wound one angel who’d grabbed him and gutting the other before escaping in a panicked flurry.