For The King

Simple - have all three party members die by having their HP go to zero. You can unequip armor and pass every turn of you want this quickly.

Note that the roguelike element kicks in here - the campaign is over and the game deletes your save. You must start your adventure over from scratch, though you retain Lore currency and any purchase you made in he Lore store in the main game menu to help you on your next journey.

The game saves automatically at the beginning of each turn/encounter so dashboarding and reloading won’t help you much while inside a dungeon unless you think you can survive the battle on the next go.