|“Yes, I know who you are. You are Vex, the Formless. I know of your lies. Formlings have never troubled us and we will not trouble them. Give him food, water, and a decent cloak and send him on his way, before his jealousy sours us all.”|
|— Grimfax after Vex attempted to persuade him|
Grimfax is the current king of the Never-Realm. Previously, he was overthrown by the Ice Emperor and Vex. He subsequently became a high-ranking Blizzard Warrior that led battles. He later rebelled and sided with Lloyd to overthrow Zane. After Zane regained his memories and destroyed the scepter that resulted in him returning to being human, Grimfax reclaimed his throne.
When Grimfax was once the king of the Never-Realm, his Warriors caught a trespassing Vex, who is brought before Grimfax. Vex tries to persuade Grimfax to attack the Formlings, but Grimfax refuses and has him thrown out.
Later, Vex returns with an amnesiac Zane who Vex proclaims as the rightful ruler. Disgusted by this audacity, Grimfax orders for them to be thrown out. However, Zane easily defeats his Warriors with his powers and puts them under his control. Grimfax is then threatened by Vex of submitting or perishing, with the odds against him, he surrenders, allowing Zane to take rule as the Ice Emperor.
Grimfax leads the Blizzard Samurai to the battle against the Great Lake.
Grimfax and his men return to the castle, with him stepping forward to report their victory. However, Vex is quick to tell him that they actually failed after displaying that the fire still remains, and how their numbers are lacking. Grimfax is stunned to learn this and tries to explain. The Ice Emperor is displeased at this and starts to freeze Grimfax, while Vex persuades him to carry out severe punishment. However, the Ice Emperor stops midway and tells Grimfax that he will atone for his mistake, much to Grimfax's relief. Following this, the Ice Emperor ordered Grimfax and his men out.
Grimfax watches Vex and two Blizzard Warriors bringing Lloyd into the Emperor's throne room, where Lloyd discovers the Ice Emperor's real identity.
Grimfax listens to Lloyd's pleas to the Ice Emperor and learns he was once a good man.
When Vex leaves the dungeon after taunting Lloyd, Vex nearly spots Grimfax, who was hiding but doesn’t see him. Making his way to the dungeon, Grimfax confers with Lloyd about his friendship with Zane and questions if he could get through to him. After Lloyd confirms this, he opens the prison doors for Lloyd and Kataru while releasing their cuffs. They form an alliance to overthrow Zane and Vex while calling themselves The Resistance.
The rebels escaped into the halls of the castle, and Grimfax told them to truly reach Zane that they needed to destroy Vex's Crystal since it would give them away.
As they traveled, Grimfax believed Vex doesn't see them coming, stating that if Vex did see them, they wouldn't have gotten this far. However, Vex had anticipated this and had the Blizzard Samurai attack Kataru and Grimfax, while the latter told Lloyd to confront Zane. Grimfax and Kataru then valiantly fight off the soldiers.
Grimfax and Kataru fought the soldiers, eventually being defeated by the overwhelming numbers. Vex mocked them both, before ordering the two to be placed in the dungeon.
Zane eventually regains his memories due to Vex taunting Lloyd by saying he couldn't protect his friends. He then destroys his scepter.
With the Ice Emperor gone, Grimfax took back to power as King and was celebrated by his followers. He later consulted with the Formlings on what to do about Vex, before it was decided that he be banished to the outskirts.
Originally, Grimfax was a benevolent ruler and did not oppose anyone. This was seen when he rejected Vex's proposal to unnecessarily attack the Formling Village because they did nothing to deserve it. He also told his men to give Vex food and supplies when kicking him out, despite the latter's anger.
After being overthrown, Grimfax submitted to Vex and Zane's demands when his life was threatened by them. He followed their orders without question, as he attacked the Great Lake and Ninja on their command. However, upon the revelation that the Ice Emperor was once a good man, he aligned with Lloyd and Kataru to overthrow Vex and his master.
In battle, he appears to have a tactical mindset, as he snuffed out the Hearth Fire of the Great Lake after seeing he couldn't beat the Ninja and Ice Fishers in battle and knew the cold would affect them later. He also chose to destroy Vex's Crystal, so his group could have a chance to surprise Vex.
- 114. "The Never-Realm"
- 115. "Fire Maker"
- 121. "Secret of The Wolf"
- 123. "My Enemy, My Friend"
- 125. "Corruption" (flashback)
- 126. "A Fragile Hope"
- 127. "Once and for All"
- 128. "Awakenings"
- The moment when Grimfax was nearly punished similarly to Harumi being choked by Garmadon in "How to Build a Dragon."
- He is the only member of the Blizzard Samurai who doesn't have a Minifigure.
- He is the only named Blizzard Samurai aside from Vex. Additionally, they both wear a helmet of the same mold.
- He is the only Blizzard Warrior that is not corrupted and instead served Vex and Zane out of fear of being destroyed.
- As a Blizzard Warrior, his signature weapon is an axe. Ironically, his voice actor, Brian Drummond, voiced a character by the name of Axl from the Nexo Knights line whose signature weapon is also an axe and is named after said weapon.
- He is also known as "King Long Beard" in one of the Ninjago Magazines.
- He is referred to as "Frost Beard" in the captions on the Cartoon Network website.