History of Corrasion (triumph)

Pattern triumph for the Corrasion pulse rifle from Episode: Echoes. Completing Deepsight Resonance extractions on it unlocks its craftable Pattern; progress is 0/5.

How to complete

1. Farm red-border (Deepsight Resonance) copies of Corrasion from Episode: Echoes activities such as Breach Executable and Echoes Battlegrounds, both launched from the H.E.L.M.
2. After Act 2 of the story you can also focus Echoes engrams at Failsafe in the H.E.L.M. for targeted drops.
3. Extract the Deepsight Resonance on five of them to unlock the Pattern.
4. With the Pattern you can craft it at the Enclave on Savathun's Throne World.

Destinypedia confirms it is craftable with 5 patterns (its article is a stub).