In most anime, the strongest military leaders aren't simply warriors—they're dynamic characters who encapsulate the ethics, power, and inner battles of the world they inhabit. These top-shelf characters must have the responsibility of defending kingdoms, battling super-powerful enemies, and serving as living representatives of their country's strength.
Prone to being both mentor and wild card in combat, they're characterized by their quirky personalities, unorthodox fighting styles, and fearsome reputations among friends and enemies alike. Black Clover, with its large and diverse cast of characters, follows suit by offering a wide range of Magic Knight Captains, each with an individually crafted identity.
Jack the Ripper, captain of the Green Mantis squad from Black Clover, is among the most interesting Magic Knight Captains. With his shaggy appearance, sadistic grin, and never-satiating craving for fighting, Jack is dreaded as well as admired. His name is not just derived from his extensive powers, but also his special magic that enables him to transform and enhance his sword and slice through anything.
Although he has an aggressive personality, he is shown as a faithful protector of the Clover Kingdom and a key character in some of the most important battles throughout the series.

Jack's magic—Slash Magic—gives him mastery over the direction and shape of his blades, to change in mid-fight to fit any defense of any enemy. He becomes a wild card and a very dangerous enemy. His violent adoration of brawls and willingness to take on stronger opponents make him worthy of the respect, as it does the apprehension, of fellow captains.
Nevertheless, his fighting abilities clearly speak for themselves, as seen in most of the wars, the defense of Clover Kingdom during the Elf Reincarnation Arc, to be exact, among other battles that occurred in the invasion of Spade Kingdom.
When he fought Dante of the Dark Triad, one of the most potent recollections Jack has is of himself. He was defeated at first, but midway, he brought himself up, using the special quality of his magic to finally inflict considerable damage on an opponent much more powerful than he was.
This proves not only his brute strength but also his tactical mindset and spirit of not giving up. Above all, he met with other characters, such as Yami Sukehiro, who anchors more dimensions of his character, juxtaposing rivalry and respect.
Jack is also very much part of the Magic Knights and has a very strong sense of duty, despite being perceived very often as cruel and unpredictable. He appreciates strength and stands by those he considers worthy enough in battle. He has a rough exterior with a heart of conscience deeply rooted within him due to many years of fighting and experience.
Jack the Ripper’s Fate in the Black Clover Manga’s Final Arcs
In the later story arcs of the Black Clover manga, Jack continues to be on the front lines fighting the most deadly threats to the kingdom. His relentless struggle against Lucifero and the other devils has been in vain, silencing the gales of destruction despite being grievously injured by these battles. He utterly exhausts himself, pouring all that remains in him into an even more stunning blow that would seal victory for his comrades-in-arms.
Ironically, he goes down in the fight, achieving one of those unforgettable deaths befitting a warrior and bringing his name into legend in the Clover Kingdom.

Jack's story isn't finished yet, but the last few seasons of the Black Clover anime, as well as the few movie adaptations, will show his important battles along with his last sacrifice. With both story closure and emotional weight, his death is treated honorably by the Black Clover manga, as the other captains contemplate his service.
In the later chapters of Black Clover, which constitute the post-epilogue period, Jack's name is immortalized alongside those who have passed, and the next generation of Magic Knights will recall his legacy as one that was both savage and heroic. His unpredictability and unyielding spirit will be the ones that inspire the next lineage.
In the end, Jack the Ripper is not a terrible captain; he is the manifestation of the wild power that Black Clover praises. His story is full of bloodshed, growth, and sacrifice, and speaks of the harsh beauty of a world where power is weighed in blood, and even chaos can be just.