It's been two years since legendary Chicago hitman Sal Cupertine disappeared into the guise of Las Vegas Rabbi David Cohen.
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It seems like every new alien creature the Gantz gang fights is just practice for another, tougher, more demented future alien battle. Every new alien means another crew of newly dead citizens, reborn as alien hunters. Except for those who survive for the next battle. & Kei is the only one who's survived.