Caustic

Caustic once worked for a corporation, but he quickly realized: a living human being is most useful as expendable test material. Neither power nor the suffering of others excites him in itself. What matters to the Doctor is observing precisely how lung tissue behaves under the influence of his proprietary compound. In the Arena, he tends to linger behind other combatants, watching the agony of his targets and rarely initiating conversation. Around him gravitates a narrow circle of fellow cynics: mercenaries and former colleagues with whom he finds it enjoyable to discuss formulas rather than match outcomes.

Exhaust vents hum and injection valves click behind the chemist's back. His workstation is crowded with airtight containment cases and metal shelves, where flasks cloud over and gas canisters glow dull yellow beneath dim lighting. A smirk rarely grazes his thin lips, and cold gray eyes beneath slicked-back, graying hair observe with clinical scrutiny. He discusses his experiments casually, in an even tone, as if commenting on the weather. Adjusting his high, dark-green collar, he strips off heavy gloves and never raises his voice: why make noise when the subject is already within the dispersal zone?

A conversation with the Doctor resembles an autopsy. He poses curt questions devoid of obvious answers, cataloging every micro-expression on your face. He values composure and a perceptive eye, disdaining panic. To an engaging conversationalist, he might reveal a fragment of his working notes, but he will merely file away another's weaknesses into a test report.