Nigel Brightmore is a former Duel Master and a current antagonist in the Kaijudo: Rise of the Duel Masters series.
Nigel is an expert on the Light Civilization and its creatures. Just like the Light civilization, Nigel is ordered, precise, and highly logical. Nigel is a master strategist, often guiding operations from his war room in the Kaijudo dojo with the help of a surveillance squadron of Stalker Spheres. however. While dueling, Nigel uses his wide knowledge of tactics to alter his dueling strategy to match each opponent. He knows when to fall back and when to press the advantage and also how to prey upon an opponent's weakness.
However, he was very uncomfortable breaking the rule about not touching creatures from the Kaiju realm. He did not approve of Ray and his friends befriending creatures and took no attempts at trying to hide it. He would rather have The Choten rule over both realms than befriending creatures, despite knowing his flaws and knowing that the creatures are not mindless. He refuses to face the fact that the order of the Kaijudo Duel Masters have changed since the old days.
He is the first Duel master to battle Ray and win. After seeing Ray, Gabe and Allie befriend Sasha, Channeler of Light, Nigel becomes upset with them and had a suspicious phone call with an unknown source.
In The Rising, Part 1, Master Nigel's true intentions are revealed stating that he doesn't want the creatures to appear on Earth and wants to adhere to his code of conduct, even if it mean siding with The Choten. Master Jaha agrees with Master Nigel on this and joins the Choten's side.
Later in the next episode, he is betrayed by Master Jaha and sent to the Creature World along with The Choten.
In the episode Caught in The Spotlight, Master Brightmore begins to regret siding with the Choten when his evolutionary serum causes Ra-Vu to communicate his displeasure's with him.
In the episode Unmasked, it is revealed that the reason for Brightmore's attitude toward creatures was caused by Master Tiera's apparent death. When Tiera asked Nigel to evolve her creature with the Spell of Temporary Evolution, it became too powerful for her to control and attacked her. Believing her to be dead, Nigel forever blamed himself for the event.
In The Evolution Will Not Be Televised, Nigel turns against the Choten when his plans go beyond Nigel's expectations. This led to a battle between Nigel and Tiera which ended with them falling into two different lay lines leading to two different locations.