Nexo Knights was a fantasy-based LEGO castle theme introduced in 2016 and based on the realm of Knighton, and follows the adventures of five young Knights who battle to defend their home from Jestro, Monstrox, and his monster army. Nexo Knights gives its characters and sets a futuristic look combining both technological and magical aspects.Nexo Knights also features a mobile app that can be interacted by using physical LEGO pieces. The theme was discontinued in 2018.