Paraphrase and make longer.
Kaiyochi is deeply committed to his role as a Demon Slayer, although he retains a slight trace of empathy for the demons he encounters. Nonetheless, he approaches his work with a relaxed and carefree attitude, not taking on weaker foes too seriously. However, when he faces a powerful demon such as one of the Twelve Kizuki, he becomes more focused and determined. Although he feels envious upon witnessing intact families, given his own experience, he suppresses this sentiment. Additionally, he takes pleasure in reading books of various genres.
Kaiyochi is fully devoted to his duty as a Demon Slayer. His unwavering dedication to exterminating the demons is admirable, but he also possesses a glimmer of compassion towards the creatures he combats. Despite this, he handles his responsibilities with an easeful and free-spirited approach, avoiding becoming too preoccupied with weaker adversaries. Yet, when he confronts formidable demons, particularly the infamous Twelve Kizuki, he transforms into a more focused and unwavering individual. Despite witnessing wholesome and unbroken families, a rarity for him, he suppresses any feelings of jealousy, recalling his own encounters with malevolent entities. Furthermore, he indulges in an assortment of literary genres, finding solace in the countless worlds conjured up by the written word.
Kaiyochi demonstrates unwavering dedication and devotion to his position as a Demon Slayer, fully immersing himself in the role, while still possessing a small fragment of understanding and compassion for the demons he crosses paths with. However, he approaches his duties with a relaxed and carefree demeanor, not allowing himself to become overly concerned with lower-level adversaries. On the contrary, when confronted with a formidable foe like one of the Twelve Kizuki, Kaiyochi's focus intensifies and his determination reaches new heights.
Despite witnessing families with unbroken bonds, a sight that triggers feelings of envy within him due to his own familial experiences, Kaiyochi manages to suppress this sentiment, displaying commendable emotional strength and resilience. Furthermore, he finds solace and enjoyment in indulging in the vast realm of literature, enthusiastically delving into books across various genres.