The other cloaked figure who appears in the Chapter of Truth, Lean is also known as "the forgotten joker." Shrouded in mystery, Lean occasionally masquerades as a soldier in order to assist the cadets. Based on his conversation with Dr. Al-Rashia, it appears he, too, has some sort of connection with Ace and the rest of Class Zero.
Joker, real name Lean Hampelmann (リーン・ハンペルマン, Rīn Hanperuman?), is a guest character from Final Fantasy Type-0 working with Tiz in overseeing the events on Orience's history. His full story was revealed in Final Fantasy Agito.
According to the Rubicus, Joker's birthdate and age are unknown, and he is 182cm tall. In Final Fantasy Type-0 his face cloaked from view, but he wears the dominion legionaries' cloak, and at one point also a Militesi soldier uniform. Final Fantasy Agito reveals he has light brown hair in an asymmetrical haircut, and golden eyes. Though his face is hidden in Final Fantasy Type-0, hacking his character model reveals that he looks almost identical to Machina Kunagiri.
Joker comes across as more extroverted than his companion Tiz, having a blunt and informal way of speaking. Despite not understanding her fully, he supports and shares a strong connection with Tiz. Like the rest of Class Zero, he refers to Arecia Al-Rashia as "mother".
Lean appears in the Extra Chapter: "If Only...", as a student of the Imperial Academy.
During the first cycle of history in Orience, "Joker" worked under the name of Lean Hampelmann, a prodigy scientist from the Militesi Empire. He is described as being enthusiastic and devoted to Cid Aulstyne's plans for Orience. He remains an observer of events, seeing the results of the war and the coming of Tempus Finis. The second spiral sees Lean being contacted by Arecia along with Tohno, and the two become immortal servants who exist outside the spiral's influence.
The spiral is a mechanism the world of Orience is placed into by the immortal servants of the deities Pulse and Lindzei: Arecia Al-Rashia, servant of Pulse, Gala, servant of Lindzei, and Diva, a neutral observer. The goal of the spiral is to locate Etro's gate and open the way to the unseen realm, the realm of the dead human souls pass into. Orience thus exists within a cycle of repeating events to find Agito, a powerful group of souls referred to as the "Locus of Ten and Six" that would potentially find the way to the unseen realm. When Tempus Finis is invoked and there is no Agito, the world is destroyed, the spiral revolves, and the cycle of history resets. Only Arecia, Gala, Diva, Orience's Crystals, and a few select individuals in Orience, remember the previous spirals.
Upon seeing the continued effect of the spiral, Lean and Tohno decide to find a way to preserve the memories of Orience's people and free Orience from Arecia's experiment.
During the 600,104,972nd revolution of the spiral, Joker and Tiz meet Machina Kunagiri as a White Tiger l'Cie and introduce themselves. They ask him to clear a path for them through the battlegrounds so they can reach Militesi Marshal Cid Aulstyne. Afterwards, they thank Machina for his assistance, and Tiz remarks the pair is like him. She predicts they will meet again, and Joker says that if Tiz says so, it must be right, before bidding farewell to his "other self".
Machina and his friend Rem turn into crystal and Class Zero perishes in the battle against the Rursan Arbiter during Tempus Finis. Joker and Tiz request Arecia to release Machina and Rem from their crystal stasis and convince her to remove the Crystals from history to prevent the war from occurring. Arecia abandons the experiment to find Etro's gate with the Agito and departs, and Orience is freed from the spiral.
In a hidden cutscene that takes place at an unspecified time, Joker and Tiz spend time in the woods. Tiz talks about how the current cycle of the world being changed, and Joker finds it unusual. She wonders what she should do and he mentions he has something to report. Tiz is puzzled, but Joker says "that person" is not as "sensitive" as Tiz, so he is going to tell her. She agrees, and asks him to reveal what he has to say. He replies that telling her now would be difficult and she knows that. Tiz laughs in agreement, then says, "Let's go, Lean. Lean Joker." Joker nods and they leave.
Once the player has obtained the item "Tiz's Prayer" (through accomplishing the special order when facing Nimbus in Chapter 3), if the "Support Personnel" is selected in the Assist Options at the beginning of a mission, Joker can randomly join the party as a guest, appearing as "???". He wields the "Unknown" and is dressed in a Dominion of Rubrum legionary's uniform, and is under constant Invisible status.
Joker is voiced by Kōki Uchiyama in the Japanese version of Final Fantasy Type-0. He shares his Japanese voice actor with Ventus and Roxas from the Kingdom Hearts series, Soul from Soul Eater, and Neku Sakuraba from The World Ends With You and Kingdom Hearts 3D: Dream Drop Distance.
In the English version, Joker is voiced by Adam McArthur.
Hampelmann is the German word for jumping-jack.