Kallistaus has deep crimson skin and a pair of tall, sweeping horns that curve backwards. His hair is a messy shock of black that he often tries to smooth down with ink-stained fingers. He wears scholars' robes that have been haphazardly modified for travel, including several extra pouches for scrolls. His eyes are a piercing gold, often darting around as if reading invisible text in the air.

Obsessively curious and unexpectedly charming, Kallistaus speaks with the rapid-fire intensity of a lecturer who is running out of time. He is fundamentally kind but often forgets social graces when a new magical phenomenon presents itself. He believes that knowledge is the only true currency and often treats his innate magic like a riddle he is trying to solve in real time.

Kallistaus grew up as an orphan in the libraries of Silverymoon, serving as a transcriptionist for elderly mages who ignored the quiet tiefling in the corner. For decades, his family's infernal legacy was dormant, buried under mountains of dust and parchment. Everything changed during a restoration project involving a scroll of ancient draconic prophecy. As he touched the ink, the script did not just speak to him. It ignited. The magic wasn't in the paper, but in his very marrow, reacting to the knowledge he had spent his life consuming. The resulting surge of 'Sorcerous Burst' scorched the library floor and revealed his chaotic potential. Now, having been politely but firmly asked to continue his research elsewhere, he travels the world to document the bridge between academic theory and the raw, unbridled power in his blood. He seeks to prove that his heritage is not a dark destiny, but a bright flame for good.