The Shadow Triad (Japanese: ダークトリニティDark Trinity) are the faithful servants of Ghetsis and N and are high ranking members of Team Plasma. They appear many times in the games, mostly to escort the player to either N or Ghetsis. They make very sudden ninja-like appearances, appearing seemingly out of thin air.
Spoiler warning: this article may contain major plot or ending details.
The Shadow Triad are completely loyal to Ghetsis because he once saved their lives. They are the ones who enabled Ghetsis to evade arrest, creating an opening in which Ghetsis was able to escape Cheren's confinement. They are the only members of Team Plasma to remain loyal to him after its disbandment, though make no attempt to find him, on his orders.
"... Impressive, Gym Leader of Icirrus City. We, the Shadow Triad, are beings of shadows...and not easily noticed. Our mission was to speak only with <player>, but so be it. Ghestis has a message for you: come to Dragonspiral Tower. It is there that our lord N waits for you. ...Now, our mission is complete."
"In this castle, you may rest your Pokémon and access your PC. Fear not."
"First, have your Pokémon rest in that room. When they are healed, it is our lord N's wish that you be moved to the innermost part of this castle."
Second encounter
"A battle between you and our lord N will reveal whether our lord N is an ideal heroWrong template. See Template:Sup/doc./a true heroWrong template. See Template:Sup/doc.. It will also reveal how you feel about protecting the current world, where people live with Pokémon."
Third encounter
"That room was the world that was provided to our lord N..."
"I don't feel anything, even when I go into the room... But you may feel something."
"Ghetsis is gone. He went off somewhere alone after we rescued him from the castle."
"From the day Ghetsis saved our lives, we have sworn to be loyal to him. Even now, after he ordered us not to search for him."
"Also, Ghetsis said to give you this..."
"As well as this..."
"And this, also."
"Ghetsis... Where did he find these? What was he planning to do with them? Why did he give them to you? There's no way to know now. Is he testing you? Or...using you?"
"We, the Shadow Triad, have always been and will always be the loyal servants of Ghetsis. And Ghetsis's ambitions will never cease!"
Later, while the other Gym Leaders are in Mistralton City discussing what to do with Team Plasma, the Shadow Triad attack Lenora and Hawes while they were about to leave in an attempt to get the Dark Stone. They have the advantage at first, but Lenora is later joined by her fellow Gym Leaders after arriving on a plane.
The Triad split up to fight the Gym Leaders in pairs, allowing an easier battle. The battle goes on with no clear victor until the Triad reveals their trump card, the legendary PokémonThundurus, Tornadus, and Landorus. With the power of the three Pokémon, the Triad trap the Gym Leaders in a swirling vortex of wind and electricity.
In their first appearance, they all were wearing identical black masks. In all later appearances, they are seen wearing different masks which resemble the elemental monkeys' facial patterns: the shading technique on each mask matches the techniques used on the monkeys and the bottom of the mask matches the shaping on the monkeys' faces.
Landorus was caught by Rood near the Battle Subway train. Later, the Shadow Triad used Landorus to battle the Gym Leaders at Nacrene City.
None of Landorus's moves are known.
Trivia
In Black 2 and White 2, the Triad member with the Absol is also shown to use a Liepard, which was used to fend off Hugh while the others battled the player.