Gloomy, beautiful, powerful, and tragic Anna / Earth-3's twisted version of Batman, Owlman
A person dies three times in their life: when they stop breathing, when they're buried, and when they're completely forgotten.
As a living scrapbook devoted to remembering her family, Anna doesn't care about anything except Luthor.
They share similar experiences and understand each other. They both lost a sister and grew stronger through that loss.
She is willing to do anything crazy for Luthor, like infiltrating the Justice League, deceiving the monsters who can monitor heartbeats, becoming the Watchtower support supervisor most beloved by superheroes, and blowing up the Watchtower, nearly wiping out the Justice League...
Even if it weren't for Luthor, she would still...
Blackmail the Justice League Dark into sinking into darkness with her for revenge, setting up Zatanna, then Swamp Thing, then Constantine.
In the apocalypse of Earth-3's corrupted superheroes invading, lead Gotham's villains in forming the "Doomsday Suicide Squad" to wage guerrilla warfare against the Crime Syndicate.
To heal her own psychological trauma, try to steal a child (Robin) from Batman.
P.S.:
Anna comes from an Inuit shamanic family that was wiped out by the Cold Flame Cult. (Like The Introverted Witch Doesn't Want to Leave Home, this story will involve folklore from the real world. That story focuses on alchemy, while this one focuses on shamanism.)
The Justice League, Justice League Dark, and the Crime Syndicate. After running through the Justice League gauntlet three times and making it out unscathed, Anna is still as gloomy, beautiful, powerful, and tragic as ever~
Owlman appears very late. There's no romance at first; Anna is just acting.
Don't be fooled by how powerful and evil Owlman seems at first. In the romance, Owlman is the lovesick puppy. If he can't have Dick, he'll go after him! If he can't have Anna, he'll die! Yandere Owlman keeps going crazy (not really).
Theme: If you don't have enough physical strength, make up for it with brains.