The Cube 1 is one of the steps in the Vexcalibur Quest in Destiny 2 that allows you to start a mission called: “//NODE.OVRD.AVALON//” quest in the European Dead Zone (EDZ), The Gulch landing zone, that rewards players with the Vexcalibur Exotic Glaive. This picture presents the Cube 1 and its location. It’s one of many steps required to complete the mission and unlock the Vexcalibur Exotic Glaive.