Grimfax

Grimfax was once the king of the Never-Realm, until he was overthrown by the Ice Emperor and Vex. He subsequently became a high-ranking Blizzard Warrior that leads battles. He later rebels and sides with Lloyd to overthrow Zane.

Corruption (flashback)
Grimfax was once king of the Never-Realm and his guards caught a trespassing Vex, who is brought before Grimfax and tries to persuade him to attack the Formlings, but he refuses and has him thrown out.

Later, Vex returns with an amnesiac Zane who he proclaims as the rightful ruler. Disgusted by this audacity, Grimfax orders for them to be thrown out. However, Zane easily defeats his Samurai with his powers and puts them under his control. Grimfax is then attacked and seeing the odds against him, he surrenders, allowing Zane to take rule as the Ice Emperor.

The Never-Realm
Grimfax is seen leading the Blizzard Samurai out of the Castle of Ice after being ordered by General Vex to destroy the villagers harboring the Ninja.

Fire Maker
Grimfax leads the Blizzard Samurai to the battle against the Great Lake.

He attacks Kai, but the rest of the Ninja save him. They prompt him to call for surrender, but Grimfax sees the Hearth Fire and is able to take it out before calling for the retreat.

Secret of The Wolf
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 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 a severe punishment. However, 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 him and his men out.

My Enemy, My Friend
Grimfax watches Vex and two Blizzard Warriors bringing Lloyd into the Emperor's throne room, where Lloyd discovers the Ice Emperor's real identity.

A Fragile Hope
Grimfax listens to Lloyd's pleas to the Ice Emperor and learns he was once a good man.

After Vex leaves the dungeon after taunting Lloyd, he nearly spots Grimfax who was hiding but doesn’t see him. Making his way to the dungeon, he opens the prison doors for Lloyd and Kataru. Then they form an alliance to overthrow Zane and Vex while calling themselves The Resistance.

Personality
Originally, Grimfax was a benevolent ruler and did not oppose anyone. This was seen when he rejected Vex's proposal to 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 threatened by them. He followed their orders without question, as he attacked the Great Lake and Ninja on their command. However, this was a facade because 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 after seeing he couldn't beat the Ninja and Ice Fishers in battle and knew the cold would affect them later.

Season 11: Secrets of the Forbidden Spinjitzu

 * 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"

Trivia

 * The moment when Grimfax was nearly punished is similar to Harumi being choked by Garmadon in "How to Build a Dragon".
 * He is currently the only member of the Blizzard Samurai who doesn't have a Minifigure.
 * He is the only named Blizzard Samurai aside from Vex.
 * He is the only Blizzard Warrior that is not corrupted and instead served Vex and Zane out of fear.
 * His signature weapon is an axe. Ironically, his voice actor 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.