Hallowed Blight tie-in is "apparently" Chapter 11, not 10.
AFAIK We've had no clues as to what's coming next.
Well they said in one of the last streams that the mysterious figure in the trailer is just a mysterious figure. And even though everything written seems to be written by Benedict it could be that the diary entries might be written by someone else. Or that that person might even be thrown into the void by the Entity.
It's hard to say right now. I'm a big fan of the theory that the Halloweed Blight lore points toward the upcoming Chapter. But considering how the writer of the diarys seems to failed to experiment, it might be possible that Vigo actually succeded that experiment by turning themself into a killer. Who knows.
If we do get Benedict I hope its as a survivor.