When Vash's bus encounters Wolfwood's motorcycle in the desert, it marks the beginning of a complex alliance. Despite their differing philosophies—Wolfwood being a proponent of martialism and Vash a pacifist—he proves to be an invaluable ally. By the series' end, he aligns with Vash's peaceful approach, though it comes at a significant personal cost. Wolfwood's mission is to fundraise for the orphanage he manages.
The enormous cross he carries has two versions. Version 1 contains twelve pistols (mounted on the arms of the cross). Version 2 houses a massive machine gun (along the long part of the cross) and a rocket launcher at the top, with ammunition stored in the cross’s arms. An alternative view suggests that one horizontal arm holds ammo for the machine gun and rocket launcher, while the other holds six pistols. The trigger for Version 2 is a skull-shaped symbol at the center of the cross. As expected, the weapon/case is incredibly heavy, but only Wolfwood, Milly, and Vash seem able to handle it effortlessly (though Vash once remarks on its weight). The weapon isn't named in the anime but is commonly referred to as "Punisher," a name derived from the manga. Wolfwood describes it as "heavy with God's mercy," a fitting statement from his cynical perspective.
He is modeled after Tortoise Matsumoto, the lead singer of the Japanese rock band Ulfuls. The name Wolfwood (ウルフウッド urufuddo) is a corruption of Ulfuls (ウルフルズ urufuruzu), which itself is a twist on the English word "soulful" (ソウルフル sōrufuru).
Nightow is often asked what the "D." in Wolfwood's name stands for. His responses vary widely, from "Dangerous" to "Dokonokuminomonjawaresumakinishiteshizumetarokakora," which translates roughly to threatening yakuza slang. These expansions reflect traits of destructive force, anger, or violence that Nightow imbued into the character.
In the original Japanese version, Wolfwood speaks in a Kansai dialect. Nightow explained this by saying, "It's an English-speaking world, so think of it as indicating some accent."
Wolfwood is actually Chapel the Evergreen's student, a member of the Gung-Ho Guns. It's suggested that Wolfwood would have inherited the title once Chapel completed his service to Knives. Chapel took in Nicholas after he escaped an abusive home situation. Raised by his alcoholic uncle whom he eventually shot dead, Nicholas's survival instinct appealed to Chapel, who raised and trained him from adolescence. Although Chapel is a professional killer, he seems to genuinely care for his ward.
Spoiler Warning for Manga Wolfwood: Raised in an orphanage, Wolfwood was later inducted into the Eye of Michael, an assassin organization founded by a plant worshipper. This group worships Knives as a god and provides contract killers. His teacher and master was Chapel, portrayed differently in the manga. During training, Wolfwood received physical enhancements including regenerative abilities triggered by a special drug, accelerating his metabolism and making him appear older than he is. In the manga, Wolfwood is over eighteen, as seen in the spin-off Freedbird where Maylene, an 18-year-old girl, was raised by Wolfwood when he was younger, implying he is at least 6 years older than her.
Shortly before the series begins, Wolfwood shoots his mentor, leaving Chapel unable to walk and assumes his Master's identity to join the Gung-Ho Guns. After the fifth moon incident, he attempts to kill Knives but is paralyzed by fear. Instead of punishing him, Knives tasks Wolfwood with protecting his brother until they meet again. This leads other Gung-Ho Guns to suspect Wolfwood's loyalty, although his actions don't directly contradict Knives' orders until Volume 8, when Wolfwood breaks into the ark to rescue Vash.
In the manga, his weapon is part of the "Punisher" series, the highest honor in the Eye of Michael. Chapel tells him his Punisher is the tenth built in the organization's 133-year history. The manga Punisher differs slightly in coloration and function, using the cross arms to hold machine gun ammunition rather than additional pistols. His "true" Eye of Michael title is Nicholas the Punisher.
