"Changed the way I live? There is no way I could have done that. I promised my allies that I would die as a soldier. Nothing else was possible. But...perhaps I could have changed my life at some point. Maybe if I had tried to change earlier in life, then perhaps I could become something else... just like you stopped killing others. I I had the strength you had, then maybe one day I, too, could have..."
Gide is a tall man Sakunosuke Oda describes as 'handsome'. he has red eyes, long white hair tied into a low ponytail that drapes over his shoulders, with only a few bangs hanging on the front from the sides, and tan skin. Underneath his dark grey cloak, he wears a light beige sweater, dark grey pants, and black knee-length boots. Both of his wrists feature black wrist cartridge holders.
Befitting a soldier, Gide is a cold and serious man with amazing leadership skills. As a soldier, he was a righteous and prideful man, smart enough to seize a walled city with 600 enemies with only 40 soldiers.
Initially, he displays himself as an emotionless man, only seeking the thrill from the war to be finally killed by his enemies. He rarely shows any emotions, with Oda being the only one whom he has shown his true character.
Desperate to die fighting to maintain his and his men's pride, he idolizes Odasaku's skill, essentially begging him to be the one to fight and kill Mimic. Despite his great respect for Odasaku, he doesn't hesitate to kidnap and slaughter the orphans Odasaku took care of as a means to push Odasaku over the edge. The thrill of the battle against Odasaku becomes Gide's main driving force. To a point, Odasaku considers Gide and Osamu Dazai similar in their wishes to die, but ultimately Gide's death wish comes from a point fundamentally different from Dazai's.
His ability, Strait is the Gate (狭き門, Sekimon?), is the same as Odasaku's, allowing Gide to predict the future for roughly five to six seconds as well. This makes Gide a formidable opponent, especially when paired with his marksmanship.
Gide used to be a hero, an astonishing commander from an unknown army during an unknown conflict called The Great War, until they are betrayed by their own country and labeled them as war criminals after attacking a walled city, not knowing about the peace treaties signed behind their backs. Therefore, their actions are unknowingly treated as war crimes and were on the verge of being annihilated, if not for they decided to take their dead enemies' possessions and disguise themselves as ghosts to break through their former allies' lines and escape.
At the ending days of the war, he and his squad - Mimic is betrayed by their country and forced to flee while disguising themselves as the enemies they had killed. From there, they wandered the lands and took on dirty work as illegal mercenaries.
Some of his comrades who were in despair chose to commit suicide. Gide couldn't do anything to stop them, but he promised they will all die as a soldier in the midst of war. With this reasoning, Mimic sought wars with organizations from Europe before being ultimately expunged from Europe by the Order of the Clock Tower. Sometime later, Mori contacted them to lure them to the country.
In the battle, Akutagawa was able to restrain Gide, but the Commander proved himself as a strong opponent, breaking free from Akutagawa's restraints all while causing the port mafia members to shoot their own comrades. Akutagawa tried to attack Gide, but Gide was able to dodge all of Rashomon attacks and land a bullet on Akutagawa's leg. Akutagawa was able to survive due to Rashomon protecting his head from Gide's bullet. Just before Gide landed a finishing blow, Oda interfered, escaping Mimic while carrying the wounded Akutagawa away.
Gide appeared some moments later, able to pursue Oda because of Akutagawa. The two fought a short battle, in which Oda and Gide both realized they possessed the same ability. Gide determined Oda as the only person that could end the war and kill him and Mimic. Oda refused the 'request', claiming he didn't want to kill because he had a dream. This enraged Gide and the former soldier fired some rounds to the unconscious Akutagawa. Oda shielded Akutagawa with his own body, revealing the bullets hit the bulletproof vest he wore under his shirt. Shortly after, Gide and Mimic left the scene after Gide proclaiming he will make Oda understand that between them, only one will survive, and he's looking forward to their battle.
Several days after the encounter, Gide decided to push Oda to the edge by killing his adopted children, causing Oda to fall into despair and throwing away his dream to become a writer. Oda went on a killing spree, storming Mimic's hideout and killing all of the soldiers in his way. He reached a grand ballroom where Gide had been waiting for him.
In his final moments, Gide tells Oda his past before coming to Japan. Oda tried to change Gide's mind, but it was useless as the former soldier only sought death. They both exchanged bullets, and Oda's bullet hit Gide. Gide told Oda that he will be seeing his fallen comrades, and he would like Oda to say hello to the children he had killed for him.
- (to Ryunosuke Akutagawa) "We are Mimic. We are a squad of ghosts - a fantomê escouade forsaken by God and fallen from grace. We shall continue to march through tainted blood until our true enemy brings us salvation." 
- "I am André Gide. We ghosts came in search of... the one who will free our souls." 
- (to Sakunosuke Oda) "Your ability to observe the future is omnipotent. No one in this world can kill you... with the exception of me. And the only one who can bury me is you. You are the sole person who can end this war." 
- (to Sakunosuke Oda) "Guns are tools to kill, this is a battlefield.SO let us fight! Let us fight with all that we are - a battle that tears away our souls! All a war needs is a single bullet. Even if you don't shoot, you will have no choice but to fight back if I do!"
- (to Sakunosuke Oda) "To live? We are already dead. We are but soulless masses of flesh controlled by the spirits of the departed. We are nothing more than empty shells waiting for an ability user like you to reduce these bodies to ash with your gunfire."
- (to Sakunosuke Oda) "If that is your answer, then there's nothing that can be done. You will not kill me because you do not understand my desire. Also, I will not kill you because you are the only one who can guide us into the battlefield's sacred fire."
- (to Sakunosuke Oda) "Changed the way I live? There is no way I could have done that. I promised my allies that I would die as a soldier. Nothing else was possible. But...perhaps I could have changed my life at some point. Maybe if I had tried to change earlier in life, then perhaps I could become something else... just like you stopped killing others. I I had the strength you had, then maybe one day I, too, could have..."
- It is unknown which country he came from, though his nationality may be French, similar to his real-life counterpart.
- His preferred weapon was a grey and slim pistol known as 'Grau Geist. The pistols may be based on European's P38.
- Him reciting a Bible passage (John 12:24), could imply that he was a religious person or at least that he possessed some knowledge about the Bible.
- In a promotional poster of André Gide, it's revealed that his ability name is "Strait is the Gate".
- He appeared as an event character for the Dark Era collaboration with the game "Kimito Lead Puzzle 18". His card is obtainable from event stages as a drop.
- According to the official guidebook: 
- He thinks his strengths include high battlefield sruvival rate of himself and his men.
- He thinks his weakness is the inability to joke with his men.
- His favorite type of woman is someone who waits for his return.
- His motto is "It is honourable to die for one’s country."
- His happy memory is the little routine between missions.