Who is the main leader of the Trio in season 6?

The main leader of the Trio in season 6 is Warren Mears.

The Trio consists of Warren Mears, Jonathan Levinson, and Andrew Wells, three human villains who combine technology, magic, and demon lore in an attempt to take over Sunnydale. Although they initially describe themselves as equal partners, Warren’s technical expertise and forceful personality quickly make him the group’s dominant figure.

Warren designs the Trio’s devices, including advanced weapons and gadgets, while Jonathan specializes in spells and Andrew in summoning demons. Their schemes begin as comic-book-style crimes, but the story becomes much darker when Warren’s misogyny and willingness to use violence emerge.

Warren is the Trio’s leader rather than its sole member. He drives the group’s escalation, kills his former girlfriend Katrina, and later accidentally shoots Tara Maclay while trying to kill Buffy. That act prompts Willow’s transformation into Dark Willow, who ultimately kills Warren. Jonathan and Andrew survive longer, but Warren remains the central antagonist of the Trio storyline.