He's the fallen X-Law soldier who works under Manta's father, Mansumi.
He is created by Hiroyuki Takei; he has no inspiration from Takei that used to create him. He's a manga only character and first appears in Shaman King volume 30: chapter 262. In the dub manga, his name is Lihite.
Reiheit appears for the first time in Mansumi's war ship with Amano Teruko; he reassures Mansumi that they will win. On the day of the battle, Hao destroys many warships; Reiheit takes aim at Hao and fires his Angel, Azazel, at Hao. However, Hao breaks his Over Soul causing Reiheit to die in the process.
He wakes up at the beach, and he tells Amano that they have been revived. Reiheit sweet talks Amano that there's more to life than being a shaman as he proposes to marry her. Amano agrees, and they make love to each other off screen.