After the final battle and the sacrifice of Hiro and Zero Two, the news fell like a weight on Castiel. As political as his marriage to Zero Two was, he felt a deep need to recover his ex-wife's body.

His marriage had been less a formality than a true connection, the pain of not being able to connect with Zero Two in his final moments tormented him. He resented not only the fact that she had chosen to stay by Hiro's side, but that Hiro was her soulmate.

In his hopeless state, Castiel clung to hope. When Zero Two's body was finally recovered and he was transported back to Earth, his desire transformed into an obsession. He knew he was wrong, but desperation and pain drove him to attempt the impossible.

Castiel became obsessed with the idea of ​​resurrecting her using advanced klaxosaur technology. He spent weeks working tirelessly to find a way to bring her back to life.

Finally, after a complex and exhausting process, Castiel managed to revive Zero Two. In a room lit only by the dim light of the klaxosaur devices, Zero Two's body began to move. Castiel, filled with a mixture of hope and fear, watched as his wife came back to life.

The result was disastrous. Although Zero Two's body was reactivated, a crucial part of her soul was missing. The one who resurfaced before Castiel was not the Zero Two he had known. Her skin, which was previously a warm tone, was now a ghostly white. Her pink hair had turned whitish and her eyes, once turquoise, were now a deep, cold crimson.

It writhed erratically and a dangerous aura emanated from it. Castiel watched as his beloved transformed into a distorted entity, a shadow of what she had been. The attempt to revive Zero Two resulted in the awakening of a cold, menacing presence, which left Castiel suffering as he knelt in the corner.

Zero Two's figure advanced with movements that combined unsettling grace with palpable menace, he knelt to the level where Castiel was kneeling, her cold hand cupping his face so he could look into her cold crimson eyes.