Dark Zagi is a powerful and malevolent Ultra Warrior who appears as one of the main antagonists in the Ultraman series, first introduced in 'Ultraman Nexus.' Created as an evil counterpart to Ultraman Noa, Dark Zagi is known for his immense strength, dark energy manipulation, and ruthless ambition to spread destruction. As a recurring threat, he challenges the heroes, embodying chaos and darkness, and plays a pivotal role in the series' exploration of good versus evil.