What does the destiny board do?

Answer 1

Official Card Text:

At the end of each of your opponent's turns, place 1 "Spirit Message" card from your hand or your Deck face-upon the field. If it is from your Deck, then shuffle your Deck. When "Spirit Message" cards "I", "N", "A", and "L" are all on your side of thefield in their proper order, you are declared the winner. If any of your "Spirit Message" cards or "Destiny Board" are removed from the field, all your "Spirit Message" cards and "Destiny Board" on the field are sent to your Graveyard immediately.

Basically, you get DB on the field, once it's effect has been used (all the other Message cards are in play) you win. It's harder than it sounds to use, as you need to find a way to protect the cards while they're in play.