|Appearances|| Last Specter|
|Other Names|| Doland Noble|
|Voice Actors|| English:|
|Relations|| Hershel Layton|
Jean Descole is the primary antagonist of the prequel series for the Professor Layton series - Professor Layton and the Eternal Diva, Professor Layton and the Last Specter, Professor Layton and the Miracle Mask, and Professor Layton and the Azran Legacy. He is extremely devious and clever, and is skilled in combat as well as logic. His main rival is Professor Layton, along with his companions Luke Triton and Emmy Altava.
Descole wears a black hat, with grey hair under it. He wears a white mask that covers his eyes, and a black suit which is covered by a grey cape. He also wears a white scarf, with black and white shoes.
He can calm and sly, but he can easily lose his temper, often resulting in battling. He mainly sticks with science with his plans and schemes. He has an obsession with uncovering the Azran Legacies.
In The Last Specter, Descole spends much of the game as a mysterious figure who seems to be seeking Misthallery's 'Healing Garden'. He kidnaps Doland Noble and Brenda Triton, disguising himself as the former, though he is eventually found out by Layton. When he is found out, Descole summons his Specter robots, which then combine to form the "Master Specter". He then takes the controls of the machine and terrorizes Layton, Luke and Emmy before being defeated by Loosha.
In The Eternal Diva, Descole reveals himself to be the mastermind behind the Eternal Life mystery that Layton and company are trying to solve. He imprisons Luke, Janice Quatlane, Amelia Ruth and Marco Brock at one point, using Amelia as another host for Melina Whistler. She was eventually rescued, and Descole told the group that his true plans were to resurrect the legendary city Ambrosia, and that he needed Melina to sing "Song of the Sea" while he played "Song of the Stars". However, Melina died so he then set about finding a way to bring her back. It is then revealed that Janice has been secretly possessed by Melina since she was used as the first subject to receive Melina's memories.
Layton and Luke set about trying to rescue Janice from Descole's hands, but he sends the Detra-Gigant organ to kill them which ultimately fails. Layton then reveals that Descole failed because there is a third song that must be played, "Song of the Sun". He then proceeds to raise Ambrosia. Furious, Descole then attacks Layton, breaking the controls of the Detra-Gigant and causing it to throw him off.
Epilogue: The City of Miracles
Professor Layton discovers that the true ringleader behind the Masked Gentleman was Descole, who was disguised as Angela Ledore the whole time. Layton revealed she was trapped in a room at the Reunion Inn, and was disguised as Mordy when she was found. Descole realizes that Layton had pretended to be taken in by his disguise until they solved the riddle of Akbadain, as he needed his help. He then regretted using Randall in his plans, as he was "pitiful" for failing. He asks Layton how he knew about his disguise, and he reveals he felt a sense of unease in the real Angela when he first spoke to her. The next time they talked, her unease had disappeared, and he was too eager to get his hands on the Mask of Order. When he had heard of Henry's mask, he needed a way to get his hands on it, and so used Randall in his plans to act as the Masked Gentleman. He thought that Henry would search for the Mask of Order if he believed that the powers of Randall's mask was real. However, he grew tired of waiting, and became Angela so he could get closer to Henry and convince him into revealing the location of the mask; he couldn't however, as he never had it. Descole applauds Layton on his explanations, but states he had "already won", and makes a quick escape.
After the Credits:
Descole is about the secure the now opened up Nautilus Chamber of Akbadain, but Targent appear, and Bronev gets out of a car to secure the chamber for himself. Many Targent members start shooting at Descole, and Bronev throws him to the ground. They try to unmask him, but before they can, Raymond throws a smoke bomb in their direction and takes off with Descole.
Chapter 5: Into the Nest
Descole is revealed to be the travelling companion of Professor Layton and the others, Desmond Sycamore, who had used Layton as part of his plan to exact his revenge on Targent, who had taken his family away. He escapes the Obsidian Tower, and Layton follows him down in a crafted glider. Raymond flies to Descole's rescue after his and Layton's sword duel, and make their escape from The Nest.
Chapter 6: The Azran Sanctuary
Professor Layton deduced that they were heading to Froenborg, and so they follow him there in the Bostonius. He is found in the Azran Sanctuary, where he was about to unlock the secrets of the Azran Civilization, but Leon Bronev stops him and takes the key. After Luke takes the key from Bronev, Emmy shows her true colors and takes Luke hostage, revealing she was working for Targent, demanding Layton to hand over the key to Bronev. Along with Aurora and Luke, Bronev and Emmy traverse further into the sanctuary, forcing Layton and Descole to team up in order to stop them.
After finding Luke in the ravine, they travel further into the sanctuary to find Bronev and stop his ambitions. Upon reaching the Chamber of Fire, one of the statues that Descole had defeated with his sword shoots a beam of light towards Luke, and so he jumps in his path in order to save him, getting severely injured in the process. It is then that Descole reveals to Layton that he was his long-lost older brother, and that their parents, being Bronev and Rachel, were kidnapped by Targent when they were young. They lived alone, however Lucille and Roland Layton decided to adopt Hershel, however Hershel was originally Descole's name. He switched their names so Layton could be adopted, while he stayed and delved into the world of archaeology for many years, in an attempt to exact revenge on Targent for taking away his family. He tells Layton and Luke to advance without him and stop Bronev.
Finale: The Azran Legacy
After the golems are released from the sanctuary, Aurora tells Professor Layton that the only way to stop them was to step into the five beams of light that were controlling them, although this would take his own life. Along with Luke, Emmy, and eventually Bronev's help, Descole also takes part in saving humanity. They all end the golems' destruction, and their lives are ended. Aurora realizes how selfless they were to save humanity, and wishes them back to life with the power of the Azran. Aurora then begins to fade, as her role was complete, and the sanctuary begins to crumble. Layton, Luke, Emmy and Bronev make their escape, while Descole remains among the crumbling rubble to make his own escape.
 After Answering the Puzzle
- "No puzzle shall stand in my way!"
- "Let's get this over with!"
- "Hah, child's play."
 Solving the Puzzle
- "Thank you, thank you, I'm here all week!"
- "But of course!"
- "Was there ever any doubt?"
 Failing the Puzzle
- "The puzzle is clearly flawed."
- "No! That's not what I meant to say!"
"Descole is a self-proclaimed scientist whose noble mannerisms conceal a cold, calculating mind. He will stop at nothing to achieve his own ends. He seeks some kind of relic from an ancient civilization, but no one knows precisely what."
"A man who would drag someone into the heart of darkness to achieve his own ends, Descole is a cold-hearted scientist who remorselessly manipulates people like puppets. He holds a vested interest in archaeology and had Randall perform a myriad of miracles for him."
"Scientist, archaeologist, inventor - Descole is a man of great intelligence, and also Layton's brother. Thoroughly acquainted with Targent's ruthless methods, his only purpose is to bring them down. If Sycamore represents the man's hope, then Descole is the manifestation of his despair."