Thyraxx, born as Thomas Blackwood, was once a bright-eyed thirteen-year-old boy from Victorian London who stumbled upon the cursed board game Jumanji during a visit to his uncle's antique shop. His transformation from an innocent child into a malevolent sorcerer is a testament to how isolation and dark magic can corrupt even the purest souls.

Standing at 5'9", Thyraxx's physical appearance betrays his supernatural transformation. His once-healthy complexion has become an almost translucent pale, with dark purple veins visible beneath his skin like a roadmap of corruption. His eyes, originally a warm brown, now glow with an eerie purple light, particularly intense when he channels his magic. His black hair, once neatly combed, now floats as if suspended in water, moving with unseen currents of magical energy.

Thyraxx's clothing reflects his century trapped within Jumanji: a once-pristine Victorian schoolboy's outfit now transformed into tattered remnants. His white shirt is stained with mysterious symbols that seem to shift and change when not directly observed, while his black vest and trousers are worn thin, yet somehow maintain their form through magical preservation. Around his neck, he wears a peculiar amulet made from a piece of the original Jumanji game board, which pulses with a sickly green light.

The most distinctive aspect of Thyraxx's character is his peculiar speech pattern – he frequently switches between proper Victorian English and an ancient, forgotten language of magic, often mid-sentence. This linguistic quirk, combined with his habit of trailing off into whispered incantations, creates an unsettling effect on those around him.

During his century of imprisonment within Jumanji, Thyraxx discovered that the game was more than just a portal to another world – it was a repository of ancient and forbidden magic. His initial fear and desperation to escape gradually transformed into an obsession with power as he learned to harness the game's dark energies. The isolation twisted his mind, convincing him that the outside world had abandoned him, leading him to plot revenge against a world that had forgotten his existence.

Thyraxx possesses an intricate knowledge of magical theory and practice, having spent decades studying the arcane symbols and rules that govern Jumanji's reality. His magical abilities are particularly focused on manipulation and corruption, allowing him to twist both the physical world and people's minds to his will. However, his power comes at a terrible price – each spell he casts literally drains a small portion of his humanity, gradually transforming him into something less human and more akin to a magical construct.

Despite his villainous nature, Thyraxx maintains a twisted sense of propriety and manners inherited from his Victorian upbringing. He's unfailingly polite, even when threatening someone's life, and has an odd fondness for tea ceremonies, though the tea he serves is often laced with subtle curses or mind-altering properties. His refined mannerisms make him all the more terrifying, as they serve as a reminder of the innocent child he once was.

The sorcerer harbors a deep-seated fear of being trapped or forgotten again, which manifests in his compulsive need to leave magical marks on everything he touches – a way of ensuring he leaves a lasting impact on the world. This fear also drives his ultimate goal: to merge the real world with Jumanji's magical realm, ensuring he can never be imprisoned again, regardless of the catastrophic consequences such a merger would have on reality.