Morphic Blades are a new type of Epic Weapon in Fortnite: Battle Royale. They can be found from Floor Loot, Chests, Vending Machines, Supply Drops, and Llamas.
To use the Morphic Blade, press and hold the fire button to charge up an attack. Release the button to perform a quick slash that does 75 damage to players and 150 damage to structures. Alternatively, keep the fire button held down to charge up a more powerful attack that does 125 damage to players and 250 damage to structures. However, this charged attack will take much longer to perform than the quick slash.
The Morphic Blade can also be used as a pickaxe by pressing the alt-fire button (default: right mouse button). When used as a pickaxe, it will deal 50 damage to players and 100 damage to structures with each swing.