Hailey for starters, is Aimee's best friend, however, one who had been part of Dragonstorm once before.
Long before getting involved in the Dragonstorm incident, Hailey was imprisoned in Kevin's machine for beating him too many times at video games. Hailey overcame many obstacles and enemies to free herself from the machine, notably killing Ace and defeating Kevin himself in a 1v1 duel. (Gamer, Gamer 2)
Her time in Trinity Facility
Hailey was in Trinity Facility for one of the sole purposes as Aimee had gone missing a while ago and in that time frame, Trinity had approached Hailey to which she soon managed to recruit Hailey into her facility. There, she had met Subject 19 and did get to know her a little bit at least. However, in the process of that happening, Trinity had also recruited three others, Marcus, Icarus and Rhino, to which the three of them, along with Hailey, became Terror Squad. Their first mission was to take down Subject 18.
Meeting Aimee again
After Subject 18 was stopped, Terror Squad arrived at the Schutzhund Competition. However, it was there where things took a turn for the worst for Terror Squad. Marcus had been killed by Jayden after Marcus had attacked both Aimee and Alfred. Rhino had been destroyed by Hans, Werner and co, along with the help of Kiara and even Hailey. Icarus in turn, was killed on the catwalks above, but not before managing to damage Alfred in the process.
Aimee gave Hailey a lengthy talk as well, telling her that Dragonstorm was not her best desicion and that she should join the good guys, to which Hailey agreeded to do so.
The Lab 101 Incident
At Lab 101, she met up with Drake once again, who in turn, managed to convince her to come back to Dragonstorm once again. And it was then that she left with Drake, well, not after having a small fight with Drake, to which she and Kiara both were defeated by him.
After Lab 101
She had been the subject of what seemed to be some sort of mind wiping power, being turned into a mindless puppet for Trinity to use at her disposal. However, in the process, she had also gained the power of pyrokenesis, able to engulf herself in flame as she had demonstrated to Shelton once she had arrived at the Idaho Prison Base with Trinity. It turns out that Hailey also has another mission at the moment, for when the time comes, to kill her best friend, Aimee.
In Las Vegas, the three formed a temporary alliance with Xanthus in order to defeat War. They succeeded, but Death appeared and killed Hailey in retaliation. He later revived her as a mindless servant, treating her as a bargaining chip for convincing Aimee to join him in his schemes. He summoned her several times in this matter, notably in Las Vegas and Texas Base. Whatever remained of her probably disappeared when Neku killed Death on the oil rig. (Disruptive Selection)
- Hailey is the protagonist of New Divide, making her the first female protagonist and the first bisexual protagonist in a Darwin's Soldiers story.
- Death referred to her as a "temporary horseman" after reviving her as his thrall. This would make her the only female Horseman of the Apocalypse.
- Hailey also appears in the Insane Cafe canon (and the tie-in story The Approaching Light.) Unlike the others, who are never connected to their canon timelines, Hailey is resurrected after her canon death in Disruptive Selection to help the villains against her will.