Fallen Shield

The Fallen Shield is an encounter in the Grasp of Avarice dungeon, and it is where the third Gjallarhorn Catalyst chest is found. Guardians get an engram from a Fallen Vandal above a waterfall, then climb the central building to reach the chest. The catalyst chests only open while a player has at least one stack of the Burdened by Riches debuff, and they do not spawn unless someone in the fireteam owns Gjallarhorn.