Karl Theodore Weierstrass

 is the current president of the Schwarzwald Republic. He is often busy so appointments must be made to even see him. He is assisted by his secretary Hes O'Neil.

Story
One day, Karl was contacted by people from the Kafra Corporation who shared his sentiments against the Rekenber Corporation. Kafra Corp. was facing aggressive competition from the Zonda Corporation, which is backed by Rekenber. Both the president and Kafra Corp. members gathered more devotees to the cause and formed Secret Wing. The president's direct contact with Kafra Corp. is the 3rd Secret Team. Secret Wing's only goal is to destroy the Rekenber Corp. and break the Schwarzwald Republic free from its oppression.

Some time later, he meets an adventurer that was sent by a member of Secret Wing. Karl is pleased to meet the adventurer and tells the adventurer about his involvement with Secret Wing and the ongoing struggle against Rekenber. He then briefs the adventurer on his/her mission and sends him/her to the Kafra Corp. headquarters in Aldebaran for the next phase of the mission.

Karl learns about Secret Wing member Jargeah's death and meets the adventurer after the delivery. It takes some time for him to look through the files due to the circumstances surrounding its acquisition, but he manages. From the files, Karl discovers that there is a Rekenber researcher name Shinokas who is hiding out in Einbroch. He then assigns the adventurer the mission of finding Shinokas, to which the adventurer reacts in surprise. When inquired further, the adventurer goes on to say that he/she had met Shinokas and that the researcher had already been killed off.

Just then, the president is interrupted by his secretary Hes O'Neil, who came to deliver more documents left by other members of Secret Wing. He looks through the new files and learns that Shinokas managed to access the Regenschirm Laboratory's Secret Archive, which was how he was able to learn so much about them. The adventurer's next mission was now to find a way to get to those archives and is sent to meet up with a Kafra Corp. employee name Esuna in Lighthalzen.

Karl meets the adventurer again, who gives him the files from the archives. According to the files, Shinokas and his friends were killed because they discovered a fragment of the Heart of Ymir. This worries the president, for he does not know the power that the fragment holds. He adds that he fears that Rekenber may be on to him and Secret Wing. He asks the adventurer to meet up with Esuna again to learn more.

The adventurer returns to tell Karl that Esuna and the other members of Secret Wing have chosen to withdraw from Schwarzwald. It appears that the organization was compromised by Karl's right-hand man and good friend Kurelle. Kurelle had always hated being in Karl's shadow and joined Rekenber in order to gain their support and beat Karl at the next presidential election. Karl is shocked and saddened by the turn of events and tells the adventurer that it is all over for them.

Time passes before Karl meets the adventurer again, this time with news that he/she teamed up with a former Regenschrim Laboratory scientist to steal Rekenber's research and destroy some of their machinery. Karl is very impressed and the news rekindles his desire to free his country from corruption, a dream he embraced when he decided he wanted to become president. He accepts the master copy of the research notes from the adventurer and assures him/her that he will do his best to fight once again.