J. Geil is the guy who killed Polnareff's sister, which is why Polnareff's so hell-bent on revenge against him.
He's best known for preferring to work in the shadows with a partner rather than going solo. That's why he and Hol Horse paired up so well—they both believe teamwork is the way to go. While Hol Horse would break glass to set up his Stand, the Emperor, J. Geil would hang back and strike at the right moment. They had some nasty combo attacks too, like Hol Horse shattering glass and firing off a bullet while J. Geil attacked simultaneously, essentially trapping their enemies in an inescapable situation.
He shared his mother's deformity: two right hands instead of one left and one right.
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