|“Their hypnotizing powers are useless if their opponent can fight without relying on his eyes.”|
|— Kai to Wu in "All of Nothing"|
When Lloyd accidentally opened the Hypnobrai Tomb, Slithraa emerged and attempted to hypnotize him. However, Lloyd slipped on the icy floor and fell out of the path of Slithraa's gaze, causing the Serpentine general to see his own reflection in an ice stalagmite and inadvertently hypnotize himself instead. This allowed Lloyd to take control of the Hypnobrai.
Later, when Lloyd commanded the Hypnobrai to raid Jamanakai Village of their candy, the Serpentine hypnotized the villagers into aiding them. When the ninja arrived, Cole retrieved the Hypnobrai Staff from Slithraa, only to be hypnotized by Skales. Due to Nya's interference, Skales was unable to issue any commands to his newest victim at the time, but the hypnotic effects would remain within the Black Ninja even after the Hypnobrai retreated and the ninja proceeded to cure the hypnotized villagers with the Hypnobrai Staff's anti-venom.
Using his hypnotic hold over Cole, Skales was able to see through the ninja's eyes, learning the location of the Hypnobrai Staff in the Monastery of Spinjitzu. When the ninja attacked Lloyd's treehouse fortress in Wildwood Forest, Skales noticed Cole and enforced his hypnosis, commanding Cole to fight his teammates. The battle gave the Serpentine time to escape and head for the Monastery of Spinjitzu, where they retrieved the Hypnobrai Staff and burned the place to the ground. Before Cole could bring down the fortress with the ninja still on it, Master Wu arrived on Flame, playing the Sacred Flute and breaking Skales's control over his pupil.
During Skales and Slithraa's Slither Pit battle, Slithraa attempted to hypnotize his treacherous subordinate, only for Skales to interrupt him with attack. After Skales defeated Slithraa, he used his new authority to force Slithraa to obey him, effectively undoing the effects of his self-inflicted hypnosis.
When the ninja raided the Serpentine's underground fortress, Skales attempted to hypnotize Kai. However, Kai countered the technique by closing his eyes and performing Spinjitzu, knocking away the Hypnobrai around him without making eye contact.
In an attempt to stop the ninja from refueling the Ultra Sonic Raider mid-race, Lord Garmadon sent a group of Serpentine to attack the ninja directly. Zane faced off with a Hypnobrai Scout on top of the Raider and turned his head 180 degrees to avoid the snake's hypnotism attempt.
- Through hypnosis, Hypnobrai can control their victims' minds and actions. Victims retain much of their personalities but twisted to serve the Hypnobrai's ends. Hypnosis victims develop red eyes with dark red spirals, somewhat resembling the eyes of a Hypnobrai Serpentine.
- Hypnotized victims can become sleeper agents, with the effects of the hypnosis in a dormant state. In this state, the Hypnobrai who hypnotized them can see through their eyes at will, and the Hypnobrai Staff's anti-venom cannot cure them. At any time, the Hypnobrai can "activate" the hypnosis within a sleeper agent, at which point they act like any other victim of the hypnosis.
- Hypnobrai hypnotism seems to be combined with Lightning on the art for Card 65 - Hypno Charge.
- It is unknown if the Hypnobrai still use their hypnotism, as they began a new age of peace with the rest of the Serpentine.
- The ability to see through the victim's eyes is similar to Zane's Falcon Vision ability.
- Cole's grandfather is the only Hypnobrai hypnotism victim to not have red eyes when being controlled.