Storied is a mechanic from The Hobbit. If you control three or more artifacts, legendaries, and/or Sagas, you get an enduring story for the rest of the game, turning on extra abilities for every storied card you control.
Storied appears mostly on legendary Dwarves, so they help each other reach the threshold. Fíli the Pathfinder gives your creatures +1/+1 with an enduring story, Thorin Oakenshield gives your artifacts and creatures ward {1}, and Balin, Loremaster can refill your hand while dealing damage to each opponent.
