Pathfinder should be immune to caustics gas. He is a robot. Not human.

@CompleatBeet Logically speaking, this doesn't prove anything, nor does it make sense.

First of all, as I stated before, Pathfinder and Revenant takes as much damage as Wattson and Wraith do. Which doesn't make sense. Either the damage has to be lower for both, or the damage for every other organic legend has to be higher. No matter what substance you would take, pretty much every acidic substance would eat through flesh much quicker than through metal. Any other way would not make it an acid, but something else entirely (Bacteria, nanobot or parasite, likely)

Furthermore, any acid would stick to the surface and last for a while. With emphasis on "a while", because it doesn't disappear quickly at all.

Lastly... Since when is Bloodhound a robot?