- Does Haise ever become Kaneki again?
- Does Kaneki get his sanity back?
- Did Kaneki lose his memories again?
- Does Kaneki remember being Haise?
- Why is Kaneki called Black Reaper?
- Is Kaneki back in season 4?
The short answer : Yes. The long answer: He regained his memories from “Ken Kaneki” inside his own head. Therefore becoming Ken Kaneki again. Yes but he now retains memory from both personality, i.e Kaneki as well as Haise.
After his defeat during the Anteiku Raid, Kaneki was taken back to the CCG, where he suffered from blindness and amnesia. Eventually, Kishou Arima would help regain his sanity by starting a new life for him. In time, however, Kaneki regained his memories of his past self and would be reunited with his old friends.
Kaneki lost his memory after Kaneki lose his memories in Tokyo Ghoul fight against Arima (CCG) where he pierced both his eyes. Thanks to Kaneki’s regenerative abilities, his brain rebuilded itself to allow him to survive, however his memories couldn’t be “regenerated” and were, unfortunately, lost.
After the fight with the One-Eyed Owl, Haise accepted he was living in someone else’s body. He now knew the life he had known was a lie, orchestrated by the manipulation of Arima. The new Haise we see after the fight is still Haise, but with Kaneki’s memory. So it is technically Kaneki.
That is Kaneki/Haise telling Urie that his friends deaths were his fault. Black Reaper is not his final state. It is what became of Sasaki Haise after getting his memories as Kaneki back all in one day. He became a dove with the callous and cold killing mechanisms of a hardened ghoul.
Based on the trailer and other teasers, Haise will go through the transition into being Kaneki again at the beginning of “Tokyo Ghoul” season 4. So, at the moment, it is best to expect that the last 122 chapters will be covered in the 12 episodes of “Tokyo Ghoul” season 4.