If Jon and Martin survived and appeared in some different reality they would also be first and at the beginning only avatars there.

So what if they started their own Institute or something in that sense. Partly to get Jon some statements he can feed on without pulling them out of people but also so they could offer to statement givers help. Either therapy or protection from the entity that hunts them or assistance if it was too late for the person and they would become avatar…

The damage is done. Fears are already in the new reality. But they can still try and deal with the guilt by helping people who will get affected by it.