“ This is an idea for a basic weapon which I have adapted partially into a fighter subclass. Let me know what you think, because if it's any good, I may post the subclass.
Double Bulwark Shield
Melee weapon (martial, shield)
Category: Items
Damage: 1d6 per hand, 1d4 together
Damage Type: Bludgeoning
Item Rarity: Standard
Weight: 6
When wielding the Double Bulwark Shield in two separate parts, you gain +2 to your AC, +1 per hand.
When wielding two separate parts of the Double Bulwark Shield, you can take an action to bring the two halves of your shield together. Your movement is halved as long as the shield is brought together. If you move or attack after bringing your shield together this turn, you receive a +3 bonus to your AC. If you don’t move or attack after switching this turn, you and an ally directly behind you receive a +5 bonus to your AC. This action is known as Steadfast.
Once the shield is brought together, you may take a bonus action to become Steadfast even if you attack this turn. However, you may not move or attack after becoming Steadfast.
Taking apart your shield is considered a free action.”
“ The PCs are accosted in a major city containing at least one famous fortuneteller / prophet of the future. They are informed that their as-yet-unborn child will (insert terrible evil), and that, although they are very sorry, the PC must be executed to keep this from happening.”
“ You find a book in the library, then when you start to read it, seems to change from pages of words to pages of images that seem to live and move. If you touch the page after the images appear, you travel into the story and now live in that world.
There is a book on that world, that leads back to this one.”