Jack Revice is a powerful alternate form of the demon Vice, partnered with Ikki Igarashi in the series Kamen Rider Revice. This form emerges when Vice and Ikki's bond is pushed to its limits, resulting in a more aggressive and unpredictable persona. Jack Revice possesses enhanced combat abilities and a new arsenal of attacks, making him a formidable ally and occasional challenge for the main heroes. He plays a crucial role in exploring the evolving relationship between human and demon in the series.