Your thing can be basically anything, but this is easiest to see if we look to Kindred decks having a critical mass of creatures of your chosen type and/or cards that care about that type is crucial to amassing synergies and building a board
Theyre powerful, immortal, and they come with a whole host of awesome powers
You can combo each of these cards with an effect that provides your permanents indestructible in order to wipe out the boards of all other players while keeping your own entirely intact
The best example of this in Adventures in the Forgotten Realms is Treasure Chest, which is a three-mana artifact
Provided you run plenty of legendary Vampires because darling, only the best are invited to the wedding you can probably keep them in play longer than you think
I suppose it also plays well with Teferi, Time Raveler against tokens or Hangarback Walker / Walking Ballista I mentioned this as a sideboard option