Rchimedes (ルキメデス Rukimedesu) or Rchimedes the 1st is the first Demon King, and the Demon King who was sealed away by the Legendary Hero about 1000 years ago. His "granddaughter" currently takes the title of Demon King.
He wears an green onesie with a white line that cuts down the middle and stitch marks seen on the waist, left leg, and right arm of the onesie. He also has black wings on his head that look just like Ruki's, but his are fake. He puts a lot of effort into making himself look "cool" by wearing red color contacts, dying his hair part black and part white and adding markings to his face and body, like the 2 lines across is nose, the swirls near his eyes, and stitch marks drawn on his neck and right calf.
In the past, he had long black hair tied back like a ponytail. He wore the usual "researcher" outfit, with a lab coat, shirt, and pants. He also wore large, round glasses that covered his eyes.
He is somewhat an idiot and quite childish personality-wise, but he was a researcher that managed to create Mana and bring magic to the world. He is very smart, as he was able to decrypt Elf's book about magic with absolutely no reference, although it was through trial-and-error.
Other than being a scientist, Rchimedes was a family man; he deeply cared for his family and would sacrifice anything for them, although sometimes he forgets to do that with his research. After Lake and his mother disappeared (via the time travel machine), Rchimedes became more obsessed about researching Mana. He became so obsessed he killed Crea to complete it and later Shion, his own son.
As the Demon King, he tends to make jokes and kid around a lot, even when he is serious.
In the original timeline, he was an avid researcher and proud father of two kids, Lake and Shion. He would research about magic to no ends, but would still care for his family. When Lake was 3 or 4 years old, he and his mother were caught in a landslide and died. He was devastated by their deaths, and became more obsessed with his research. Sometime later, it is hinted he created magic, and went on a rampage with it. After Ross and Crea defeated him, magic was lost in the world, until Alba recreated Mana.
After Elf's interference, he discovered Mana early on, and repeatedly tried to create it. He had Elf's book with him, and therefore had more information to go to, although it wasn't much. However, Elf later left him a time travel machine, which he unknowingly brought home. Lake, who was only 3 or 4 years old at the time, played with the machine and sent himself and his mother to the future. Devastated by their disappearances by the machine, which he mistook as them being killed by it, lost his sanity and became more obsessed with his research.
With his Mana Maker-kun, he has a next-to-infinite amount of Mana to use magic on. However, he could only replenish his Mana with 'Ma', hatred. He is rather adept at using magic, even more than Ross, but Ross bests him in physical ability. However, with Mana, his physical abilities could be on par with Ross'.
- It is noted by Ross that Rchimedes has a "terrible fashion sense"
- His name is based on the mathematician Archimedes from a suggestion by Haruhara's friend.
- Mana Maker-kun is Rchimedes' invention, but in Elf's timeline, Mana Maker-kun is Alba's invention, although not in the same fashion.