Kaisar Lidfald is a central character in the anime Rage of Bahamut: Genesis, whose life is marked by a dramatic fall from grace and a subsequent quest for redemption. Born the heir to the prestigious Lidfard family of knights, Kaisar endured a strict and exhausting childhood under his father's demanding tutelage, a pressure that caused him to rebel and distance himself from his family. This tragic backstory culminated in an incident where his father was tasked with guarding a royal tribute. The convoy was ambushed by bandits, and his father was publicly disgraced and executed for the failure. Stripped of their noble status and banished, Kaisar's family lost everything, leading his mother to take her own life half a year later. Consumed by grief and a burning desire for revenge, Kaisar came to believe that the bounty hunter Favaro Leone was the man responsible for the ruin of his family, vowing to track him down and restore his family's honor.

To pursue Favaro, Kaisar became a bounty hunter himself. In terms of personality, Kaisar is defined by a rigid and unwavering sense of honor and justice. He is a righteous man who consistently follows his own idealistic moral code, which often puts him at odds with the more roguish and carefree Favaro. Despite his stern and sometimes stubborn exterior, Kaisar is deeply empathetic and compassionate. This is notably demonstrated when he stumbles into a village of the undead controlled by a young necromancer named Rita. Overwhelmed by the illusion of a happy family life they project, he shows great kindness, and upon discovering the tragic truth, he still chooses to spare the immortal Rita, forming a lasting bond with her. His own tragic past makes him highly value familial bonds and scorn those who take their loved ones for granted.

Kaisar's primary motivation for much of the first series is his revenge against Favaro. However, as he becomes entangled in a larger conflict concerning the awakening of the ancient dragon Bahamut, his goals shift. While pursuing Favaro, he encounters Amira, a mysterious half-demon, half-angel girl who holds the key to Bahamut's seal. Kaisar's role in the story evolves from being a simple pursuer to an unwilling, and eventually willing, ally. His drive for revenge is turned on its head when he discovers that the true architect of his family's downfall is not Favaro, but the fallen angel Azazel. This revelation forces him to re-evaluate his vendetta and join forces with his former enemy to prevent the apocalypse.

Kaisar's key relationships are central to his character development. His relationship with Favaro Leone is the most significant; it transforms from bitter enmity to a complex, grudging partnership and ultimately to a genuine friendship built on mutual respect. His relationship with Rita is one of profound care and protection, with the young zombie frequently acting as his moral anchor and rescuer. In the second series, Rage of Bahamut: Virgin Soul, set ten years later, Kaisar has recovered his noble title and honor, serving as a knight captain under the new king, Charioce XVII. His loyalty to the king becomes absolute, to the point of willingly enduring imprisonment and fighting in a coliseum for the king's amusement, showcasing a new layer of devotion that supersedes even his personal freedom.

Throughout his journey, Kaisar undergoes significant development. He begins as a bitter, revenge-obsessed former noble clinging to the past. Through his adventures and forced cooperation with his sworn enemy, he learns to let go of his hatred and accept a more complex reality. He matures from a hot-headed youth into a seasoned, loyal, and duty-bound knight. Notably, in the climax of the first series, he willingly allows Favaro to cut off his left wrist as part of a desperate plan to seal away the mastermind, demonstrating immense trust and sacrifice. He later receives a prosthetic hand, a physical mark of his harrowing journey and the lengths to which he will go to protect the world.

As a fighter, Kaisar is a highly skilled swordsman, trained from childhood in the knightly arts. He wears distinctive green and white attire and often dons gray armor in battle. In his pursuit of Favaro, he acquires a Bounty Hunter's Bracer, a device that allows him to seal demons into cards to claim their bounties. This tool proves crucial in the final battle against the revived Bahamut. While he is a capable and determined warrior, Kaisar's most defining trait is not a supernatural ability but his unyielding resolve, his strong sense of duty, and his deep-seated compassion, which ultimately guide his actions more than any quest for revenge ever could.