Which is the timeline where Vegeks Xeno appear? I was reading the Super Dragon Ball Heroes manga and it was more or less similar to the anime until chapter #3. There,


   Vegeta fights with Cell and after defeats him, he's attacked by a "demon god", knocking him out and forcing Trunks to use potara rings to fuse with him into Vegeks Xeno


Which is the timeline where this Vegeks Xeno appear?
It is an alternate timeline of the Age 767. This is basically the year when all the events involving the Androids and the Cell Games take place.