Good question! We want to ensure the character arrival mechanic functions as flexibly as possible, so we don't want to say there's only one right answer.

But to actually give some practical options: you could definitely go the "well, I almost died" route! You could also potentially involve some kind of Questionable Space Being that happened to catch a character just at the precipice of walking into That Bright Light. You can also avoid a canon point like that, if it makes more sense for you.

Honestly, we're happy to let you decide whatever makes the most sense for your character who may or may not be actually dead in canon! We're also happy to work with prospective players should they need help brainstorming a way to ICly get their character involved.