Even after fusing his body with various Gogmagog, he was killed by the combined strength of 'wolf-woman' Rio, Coco and Joe.
Simon is a tall man with slick back hair. He wears a monocle over his left eye to cover his blinded eye. After his battle with Arago, he now has a burn scar on the left side of his face. Simon is usually depicted with a black suit.
When Simon was first met, he appeared to be a kind man. He was very polite and formal.
His true personality is that of a cruel and heartless doctor; to the point of kidnapping Coco, and using her to get to Arago. He also kills a lot of gremlins to use their spirits to create a golem. Like the other horsemen, Simon holds Patchman in high regards, referring to him as "His Majesty"
Simon first appears to us in Chapter 38, after Arago finds all the gremlins dead, for which Simon is responsible.
Afterwards Simon appears complaining to himself in his lab about why the Patchman let Lucian join them. Simon then says that he is going to corner Arago and torment him, and starts to make a golem with his Seed.
Simon makes a full appearance when his golem is found dead in a park. Coco runs into him by mistake, and he says that he is a police consultant. As he is looking at the body he comments on its condition.
While he works on his next golem, Simon wonders if Arago will be enraged after seeing his next work. He then sends out the golem to attack Arago while he is in the middle of his training. Simon watches Arago as he faced the golem. He also comments on how Arago fares. As the battle comes to an end Simon says that although his golem has been destroyed, the battle wasn't a complete waste and he has collected some useful information stating that he found out what Arago's biggest weakness is.
After the battle Simon kidnaps Coco. He locks Colo in a cage by piercing one of his legs with a cage bar. Simon then brings Coco to his lab and waits for Arago to show up and rescue her, having left a clue for them to follow him.
As Arago arrives to his clinic, he reveals himself as the Black Horseman. Simon then kills the gremlin he kept alive, in order to create his new golem. He now reveals to them where Coco is. He had fused her with a bear and a lion to create his new golem. Simon then orders the golem to kill Joe, who is trying to free Coco. He says that the golem's claws have surpassed Arago's regenerating ability and that he won't attack it as long as Coco is fused with it. He reveals that if Arago destroys a device on the golem, Coco dies. As Arago fights the golem, Simon laughs at him for being weak against it. The Horseman is shocked when Arago is able to free Coco from the golem, un-fused her at a cellular level.
Simon then faces Arago in a one on one battle. He fuses Arago with a table so he can't move. After Arago grins at him he fills the air with carbon monoxide to kill Arago, before fuses a chainsaw to his own hand. Arago frees himself from the fusion and charges to attack the doctor. While Arago attacks him, he fights back with the chainsaw. Arago punches him and the power of Brionac burns his face. Simon is rescued by Lucian, but first he makes Simon ask for help twice. Simon then says that he will never forgive Arago for the wound he gave him, before leaving with Lucian. Later he is shown in a sewer with the other horsemen, leading to the seals that protect the cauldron.
A flash back is shown of him being a doctor and trying to cure a patient with a disease that affected her circulatory system. To give the patient a hope of living, Dr. Simon continue to research for the cure. The patient was treated and she was healing miraculously. By this time, Dr. Simon has fallen in love with the patient.
When Simon was going back to the hospital to celebrate her discharge (not without buying a wrist watch for her), she apparently jumped out a window. A shard of glass stabbed him in his eye, blinding his left eye. Dr. Simon try his best to put the patient's pieces back together but fail to do so. This event leaves him with a scar in his mentality.
Seconds later Patchman appeared, saying "Just like excited little maggots, hope is something lost on humans. The only power you can give them is despair ... Don't you agree?" then promptly giving him his powers.
The Black Horseman's seed allows him to fuse together living organisms and non-living objects. In addition, he is able to remove life from creatures and create artificial seeds, which he uses to create Golems.
His role as the horseman who symbolizes famine may be due to his power of fusion. Though it might also refer to his 'hunger' for new experiment and subject.
- Imbalance: By fusing an inorganic object with one that is organic he is able impede their movement.
- Dr. Simon is somewhat a reminiscent of the character Dr. Jekyll in Robert Louis Stevenson's "Strange Case of Dr. Jekyll and Mr. Hyde" in which both of them is a good doctor with a strange, twisted secret; Mr. Hyde for Dr. Jekyll and seed for Dr. Simon.