Wayfaring for Second Chances
No mounts are allowed. Everywhere the party goes, they must go on foot.
When creating characters, each player must have a horrible experience from their past, a moment where if they had just done one thing differently, made one different choice, they feel everything would be better.
However many adventurers there are, the chalice of second chances will grant the opportunity to one less. (5 players = 4 chances.) This is not known until they get there.
The chalice cannot be reached until the party has bonded, until everyone deeply cares that the others get the chance. The first player to drink must ask to grant the second chance wishes of all the others, but that player's character will forever become part of the chalice. To never live or die, to never be free, a magic that could only be undone if someone else went on the quest for a second chance to be the one to drink. Except the chalice of second chances only grants one second chance per being, ever, so none of the party members can be the one to do this.
While the second chance might go well (the dice determines that), the player swill forever be racked with guilt (regardless of alignment) at the loss of their party member.