Luis "Grandmaster" Castillo is a fighting games player from the Dominican Republic currently representing Topsietegames.

Grandmaster is also known to compete in Mortal Kombat 11, Guilty Gear Strive, Injustice 2, Super Smash Bros, Dragon Ball FighterZ, and has participated in tournaments like Rumble in the Jungle, First Kiss GG Strive, First Attack 2020 Online, MK11 Liga Latina - Latam Norte, Take the Throne - LATAM Norte, and Blink Fighting Fest 2020.