Mach is a character from the anime Yu-Gi-Oh! Zexal II, where he appears as the spirit of the Number card Number 44: Sky Pegasus. Originally, Mach was the pegasus steed of the Barian Emperor Dumon, serving as his loyal mount. After Dumon's role changed, Mach evolved into a Number Guardian, tasked with protecting his Mythyrian Number form. His primary motivation is to safeguard the Number until a worthy duelist proves capable of wielding its power. In the story, Mach acts as a gatekeeper, challenging Yuma Tsukumo and Astral to a duel to test their worthiness. He possesses the ability to see Astral, which indicates his spiritual nature and connection to the Astral World. His personality is defined by a sense of duty and pride as a guardian, and he shows respect for those who demonstrate true strength and resolve. Key relationships include his original bond with Dumon and his eventual respect for Yuma and Astral after they pass his test. His development is minimal, as he exists primarily as a trial for the protagonists, but he transitions from a mere steed to a sentient guardian with his own will. Notable abilities include his dueling skills associated with Sky Pegasus and his capacity to manifest as a spirit.