“Stronger now are the people of the Maple World, but still not enough to defeat the Black Mage.”
- ― Von Leon
Von Leon was the king of Lion King's Castle in El Nath Mts.. Many people were loyal and devoted to him to the extent of some people whom have already passed away (turned into ghost) chose to remain loyal to him but could not rest in peace due Von Leon's turning into a villain. The loyal servants of his then decided that Von Leon should be killed, as much as they didn't want to, but they believed that the old Von Leon would appreciate their thinking.
A hundred years ago, Von Leon's wife Ifia was murdered. He found a Cygnus Knight crest on her body which made him believe that they did it. This was all actually a set-up for him to join the Black Mage, which he did. After the Black Mage was sealed, Von Leon casted a spell which killed every resident in the village and his castle disappeared; the moment the Black Mage were to return, Von Leon would too.
Like the servants, his ghost wife was also not at peace. She tried to reach out to Von Leon, but he could not see her because he went too far in his villainy and could not turn back.
In Demon's story, Von Leon attended a meeting with Orchid, Arkarium and the Demon. He would act as a mediator between Arkarium and the other two, as Arkarium's snarky attitude would often lead the meeting nowhere. Later as the Demon has grown in strength and makes way to the Lion King's Castle in demand of questions, the Lion King says he has no quarrels with traitors and kicks him out of his castle.
In the Grand Athenaeum Chapter 4, Von Leon was discussing plans to attack Ereve with Hilla. When they notice Ryude eavesdropping Von Leon tries to kill him, saying that he remembers the mercenary from years ago. He overpowers him and asks for the mercenary's name. He refuses and just when Von Leon was about to kill him, Alicia rescued him. Later, Von Leon leads his forces to raid the Dragon Masters Tower. Arriving a second too late, Von Leon once again asked the mercenary for his name, for him to answer: Ryude. Von Leon commends Ryude for fighting well.
- A photograph found in the Monster Park shows Von Leon with Spiegelmann. Seeing as Von Leon looks happy in the picture, it was presumably taken before his wife's death. (If it is shown to Spieglemann, he'll bribe the player into keeping quiet about it.)
- There's a beggar in El Nath named Nonvon Leon who looks like Von Leon.
- In Demon's storyline, the player is able to find a secret passage to the Throne Room where Von Leon is in the entrance to the Castle, but it can only be used once after the quest is completed and Demon is kicked out by Von Leon.