Okay, I'm sort of brainstorming out loud here. Other people definitely seem to be going for some intriguing, thoughtful, and suspenseful options in the conversation, so I'm going the opposite route.
It's a standard fantasy dungeon crawl, with characters who only have 1 HP, and every time you die, you bring in a "brand new" character who is clearly just the original character with a single feature changed, and give an unconvincing explanation for how they got this far alone to join the party.
The game continues until the final boss is defeated or until players run out of ideas for ludicrous twins, clones, cousins, children, people with fake beards, etc.