Zak Saturday is a young boy, who is the reincarnation of Kur, one of the most dangerous forces in the universe. With his powers he can manipulate a powerful orange energy, and control cryptids. Despite this, Zak uses his powers for good. Zak was briefly killed when he fell during the loss of his world, but was brought back by Thomas. In the future, he is married to Wadi, who is expecting. He is shown to be good friends with Ben Tennyson
It is shown in a possible future that an evil zak could lead to the destruction of many worlds, control over dragons and other non humans and the death of Omi, Grievous, Durza, Julian and Doofesmirtz. It is shown here that his power extends to any non human species, however Elves, Robots and cats appear immune. Also Dhampires like Remenesse are also immune to his control, due to being half human.