In "Battle Nexus: New York," Big Mama secretly attached a control device and it's associated magic ring to the Shredder, and controlled him under the alias of Shadow Fiend. This was discovered during the Turtles, Splinter, April, and the redeemed and recovering Draxum's fight with Big Mama. When the ring was removed from Big Mama during the fight, the Foot Recruit claimed it. Before Leonardo could portal Big Mama out during their escape, she got cut off. The Foot Recruit, furious that her master was enslaved, sinisterly told Big Mama that she was about to lose everything and advised her to run. The Shredder then destroyed the Grand Nexus Hotel, flying out into the city with the Foot Recruit on his back.