Takaya is the charismatic leader of Strega and the Main Character's rival, positioning himself as a false messiah among Persona-users. He's confident to the point of arrogance, and he sets up his group as the story's opposing force.
In combat, Takaya relies on a six-shot revolver. What makes him stand out mechanically is how he summons his Persona—he does it manually, clutching his head and dropping to his knees, which actually seems to cause him pain. Aigis is the only other Persona-user in the game who doesn't need an Evoker, though interestingly, Persona-users from earlier games didn't use them either and showed no visible strain from summoning.
The key to understanding Takaya is his terminal illness. Knowing he doesn't have much time left, he's decided to live recklessly in the present moment, unconcerned with collateral damage. His actual goal is pretty dark—he wants to see the world end when he does. He has some genuine affection for Jin and Chidori, but that doesn't stop him from treating them as expendable tools when it suits him.
His motivations shift partway through the story. Initially, he seems to be trying to prevent SEES from killing the twelve Arcana Shadows, as if he's actually trying to save humanity. But once he understands what those Shadows really are, he stops pretending and fully embraces the apocalypse. Near the game's climax, he establishes a full cult around Nyx's arrival, casting himself as its high priest.
Takaya's defeat comes when he attempts to physically stop SEES from ascending Tartarus to confront Nyx. Afterward, he crawls up the tower anyway to witness the final battle himself. Whether he survives once the Main Character seals Nyx away is left ambiguous, though given his dependence on lethal suppressant drugs just to stay alive, his remaining lifespan would be short either way.
Content compiled by AnimeList.moe from publicly available sources.