It sounds like you're referring to — a notable channel on YouTube that featured young brothers (often called the "Fighting Kids" or "Fighting Brothers") engaging in choreographed martial arts, tricking, and fight scenes.
Learning to navigate physical challenges in a controlled setting helps children build self-esteem and the ability to handle adversity. The Role of Video Platforms in Training Fightingkids.com Youtube
: The main Fightingkids channel was terminated multiple times for violating policies on child safety "FightingKids" It sounds like you're referring to —