There is no theme for this jam.
You do not need to include the guardian knight in your quest submission. It is only the grand prize!
You can of course recreate any content that you have already made, and submit it.
You get to decide whether the player starts with one hero or more, brand new or seasoned or a combination of the two. You can also decide what gear the heroes get at the beginning of the quest (use quest notes to specify). If nothing is specified, a default hero party is assumed.
If using the classic HQ style map, I'll assume a standard Barbarian, Dwarf, Elf and Wizard party.
If using the 2021 HQ style, I'll use any of the heroes that have been introduced since that edition, unless restrictions are specified in the quest notes (i.e No Bards, etc.).