Fran is newest member of Vongola's assassination squad Varia, who appears in Future arc. He is shown to be replacement for Mammon (Viper), after Viper's death, and is shown to use one of the Hell Rings (the 666 one).
Fran is the newest officer member of the Varia in the Future who uses a Hell Ring with the numbers "666" (number of the beast) imprinted on it. Introduced during the Varia attack on a Millefiore base in Italy, Flan is Mammon's replacement as the group's illusionist and is thus forced to wear a large frog hat to symbolize this. Fran has a calm demeanor despite being very antagonistic towards the other people, constantly verbally attacking them. According to Reborn! Volume 25, his profile is top secret, but he was featured alongside Bel in Reborn's Weekly Horoscope as a Sagittarius. It was later revealed that his master is Mukuro Rokudo, who was released from the Vendicare Prison thanks to Fran's help.
Merone Base Invasion Fran participated in the invasion and subsequent defense of a Millefiore Base in Italy in the same time frame as the Melone Base Invasion by Tsuna's Family. Flan was paired with Belphegor and ordered to explore the surrounding area to the base and fight any Millefiore soldiers they found. After Belphegor dispatched a number of Millefiore Soldiers (and a large section of forest), they came across Olgert, and very much to their surprise, Bel's supposedly dead twin brother - Rasiel. When it came time to fight, Flan couldn't open his Box due to the fact that he needs to do a hero-like pose before opening his Box. He couldn't do his usual pose because it involves reaching over his head, which he couldn't reach because of the frog hat. After Rasiel incapacitated Bel, Fran was able to create an Illusion and escaped, partially to save their lives and partially to witness Xanxus fighting with Rasiel.
Future Final Battle Arc
According to Lussuria, Flan went to visit a girl whose name was W.W after the Millefiore Castle Invasion. The romanized translation of what Lussuria said was "Daburyu," which is the letter W. It is later revealed that Flan went to Vendicare Prison to help Mukuro Rokudo escape prison by posing as members of the Millefiore Famiglia. The Milliefore Familgia were about to release Ghost only to find that someone has posed as members from their family and released Mukuro Rokudo. Flan is later seen at a hideout with the girl that was revealed to be M.M., who was there with Ken Joshima and Chikusa Kakimoto. M.M. scolds Flan for putting her bag upside-down and for sneezing on her expensive coat. Flan complains that he always get scolded for everything, even though he was the one who had helped Mukuro escape. Chikusa says that Mukuro will need some time to recover, since he had been floating in a tank of water for ten years. Later on, in the final battle between the Vongola and Millefiore Famiglia, Kikyo, Zakuro, and Bluebell, who have seemingly killed the entire Vongola Famiglia, are attacked by illusions created by Mukuro. Flan, who reappeared beside Mukuro, complained that Mukuro had taken the "spotlight" again and that the people that they believed to have killed were really an Illusion, and that the Real Funeral Wreaths had in fact killed no one. Belphegor, who felt a bit annoyed by how the illusion worked out, complained whether they really had to die in the illusion. Flan responded that illusions had to be "realistic" and that "illusion were somewhat like pranks." Mukuro said that he was wrong and comically stabbed Flan in the head, which shocked Lussuria and Ryohei. Mukuro said that the real reason was to find data on the Six Funeral Wreaths, and to serve as a warm up. Bel, who still believes that the illusion was still ongoing, asked how long the illusion will last. Flan reassures everyone that "pineapple hair isn't an illusion" and that he helped escape from Vendicare. Kikyo applauded Mukuro's apprentince for hoodwinking Vendicare, and Flan told Mukuro that he was a celebrity now, but Mukuro once again stabs him in the head to silence him. Flan then told everyone that the rehearsal was over since the the Funeral Wreaths that have fully healed from the attack earlier are ready to wipe them out again. Flan tells Mukuro he should sit down because he just got his strength back or wait until his Vongola Box got there. Just when the two sides have began to fight again, out of nowhere, Ghost arrives on the battlefield.
Ghost then started to drain Flan's Dying Will Flames along with everyone else that is present. The Varia started to attack Ghost, but to only find out that it had no use. After the battle, the rest of the Varia head back to Italy.
Illusions - Flan, being Mukuro's disciple, is a powerful illusionist, capable of fooling a Fake Funeral Wreath, and is one of the three illusionists capable of fooling the Vendice.
Bel Box Weapon - Flan has a Box Weapon that is a miniature version of Belphegor covered with Mist Flames.
Hell Ring- Flan has the 666 Hell Ring.
-In the Reborn! Fandom, his number is 26.
-In the DS Games, his Box Weapon is shown to be a big grey toad, exactly like his hat, but in the series, it is a minature Bel with -Mist Flames.
-Flan seems capable of withstanding pain. This is seen when he is hit in the head with many Knives and even Mukuro's Trident, yet he still shows a calm face.
-Flan's frog hat shrinks and wrinkles when his flames are being sucked away.
-He is forced by Bel to wear a frog hat that symbolizes Mammon.
-In a recent popularity poll, Flan ranked 11th.
-Flan has a character song, Special Illusion.
-In the "Dream Match-Up" Polls, Reborn stated that Flan is a genius, like Belphegor.