Acid Trip requires you to kill enemies with Corrosive damage. You can work on this when fighting Loaders, as they are weak to Corrosive weapons. Any Corrosive weapon will do, even grenades, and even Maya's Cloud Kill skill will work. Basically, if you see green numbers when doing damage and it's the thing that kills the enemy, it will count towards this.
- Rank 1: Kill 20 enemies with corrode damage
- Rank 2: Kill 75 enemies with corrode damage
- Rank 3: Kill 250 enemies with corrode damage
- Rank 4: Kill 600 enemies with corrode damage
- Rank 5: Kill 1000 enemies with corrode damage
