Unlock Location:
- Progress through the story until reaching southwest of The Terminus Range.
- The Drill sight is just north past the first bridge form the Stoneblood Forest Fast travel station.
- Complete the Drill Sight called "The Lowering March" and at the end you will face The Battle Wagon.
Farm Method:
- Defeat The Battle Wagon in The Lowering March Drill sight.
- After use the Encore Machine nearby to reset the fight.
- Repeatedly defeat The Battle Wagon until
Finnity XXX-L drops.