Julio Esteban Richter

Peter David's X-Factor run is legendary for its street-level, noir-tinged take on Marvel's mutant world, and Julio Esteban Richter is one of the compelling figures who inhabits that corner of the universe. Debuting in 2008 during the Modern Age, this character moves through a rich ensemble that includes powerhouses like Multiple Man, Jamie Madrox, M, and Monet St. Croix — some of Marvel's most complex and underappreciated personalities. Appearing across X-Factor and its spin-off specials like Happenings in Vegas and Invisible Woman Has Vanished, Richter is woven into one of the most critically beloved indie-feeling superhero series of his era. With 34 catalog appearances concentrated in a tight, purposeful window, he's the kind of character that rewards deep-dive readers who want their comics dense with character and consequence.