Captain Jekyll is a skilled swordsman featured in the anime, commanding attention with his exceptional combat abilities. He served as Diego de la Vega's senior classman during their time together in Spain, significantly shaping Diego's path by teaching him advanced fencing techniques. This mentorship formed the core foundation for Diego's swordsmanship, skills essential to his alter ego, Zorro.

Jekyll's perceptive insight surfaces during a confrontation with Zorro. He recognizes distinctive elements of Diego's fencing stance and techniques—elements he personally taught—allowing him to deduce Zorro's true identity as Diego, highlighting their deep shared history and Jekyll's familiarity with Diego's fighting style.

Beyond mentorship, Jekyll occasionally allies with Zorro against common adversaries. In one documented instance, he and Zorro engage in coordinated combat against the Scorpions gang, culminating in a back-to-back fighting stance that showcases their mutual combat effectiveness. Jekyll's combat prowess remains consistently formidable, with specific emphasis on his mastery of the rapier.