Emilio Hernandez was born on July 2, 1996, in the United States. Demonstrating natural athleticism from a young age, he actively participated in multiple sports, including baseball, basketball, track and field, and soccer. Soccer became his primary focus, which he pursued consistently from age five through high school graduation. At 14, Hernandez experienced a significant life transition when he relocated to Spring Hill, Tennessee, to live with his aunt. This move marked a challenging period, as it was his first extended separation from his parents.

Seeking an outlet to manage the stress and anxiety from his relocation, Emilio began training Brazilian Jiu-Jitsu in August 2010 at a local mixed martial arts gym in Columbia, Tennessee, under coach Keefe Cothran. After one year, recognizing his passion for grappling, Hernandez transitioned to a specialized academy, joining Tennessee Brazilian Jiu-Jitsu Academy under instructor Ray Casias. He quickly immersed himself in competitive grappling, making a pivotal decision at purple belt to dedicate himself exclusively to jiu-jitsu competition.

On July 22, 2019, Emilio Hernandez received his black belt from Ray Casias. He rapidly established himself as a formidable competitor on the international no-gi circuit, consistently achieving podium finishes at prestigious tournaments. During the 2021–2022 season, Hernandez reached a career milestone by securing a top-five IBJJF world ranking in the adult black belt division, peaking at number four. His notable accomplishments include gold medals at the IBJJF Pan American No-Gi Championship and the Toronto No-Gi Open, solidifying his reputation as a premier no-gi specialist.

Emilio Hernandez earned the nickname "Scramble King" due to his exceptional scrambling ability and dynamic grappling style. Known for his aggressive pace and relentless pressure, Hernandez consistently engages opponents in fast-paced exchanges, creating opportunities through controlled chaos. His scramble-heavy approach distinguishes him from his peers, making him a standout competitor and significantly contributing to his competitive success.

In 2021, Hernandez relocated permanently from his native Washington state to Tennessee to further advance his training and competitive career. Initially, he spent a year training under coach Keefe Cothran in Columbia before returning to Tennessee Brazilian Jiu-Jitsu Academy in Spring Hill under Ray Casias. Beyond competition, Hernandez actively embraced coaching responsibilities at the academy, significantly contributing to the development of local talent and playing a pivotal role in the growth of Zenith BJJ in the U.S. South.

In addition to his grappling achievements, Emilio Hernandez briefly ventured into amateur mixed martial arts competition. He compiled an impressive 3-0 record, securing all victories via submission. Following this successful stint in MMA, Hernandez chose to refocus exclusively on grappling, channeling his efforts into furthering his accomplishments on the international jiu-jitsu stage.