'''A Hundredfold Path''' is the catalyst quest for the One for All perk on Barrow-Dyad. It is unlocked in Act 3 of Heresy by completing the Sunless Cell strike with Barrow-Dyad equipped. The strike is available from The Last City under Destinations.
Walkthrough
Complete Sunless Cell with Barrow-Dyad equipped. This grants the quest and a fragment.
Bring the fragment to the Shaping Slab in Eris' apartment to start the quest.
Toggle the Path of Ambition in Eris' apartment, making sure the orb next to the Shaping Slab is glowing white.
In The Nether on the Dreadnaught, collect all ten Tithing Wormspawn. There are two in each area. Two of them are in the Hull Breach tile, which only appears in The Nether's second and third encounters and spawns infrequently.
Clear Sunless Cell again with Barrow-Dyad equipped, using Submachine Guns, Auto Rifles or Machine Guns in the Energy and Power slots. The catalyst is then yours and is forged onto your weapon at the Enclave.