History

Simon is a young boy with an interest in science who attends Smallville High alongside Conner Kent. Upon meeting Legionnaire Tellus in a Smallville Swamp we learn he is destined to be Superboy's greatest friend and greatest enemy. During the Blackest Night, he is one of the people controlled by the Black Lantern, Psycho Pirate into rioting in the streets. 
Superboy: Smallville Attacks

Conner is confronted by his new best friend Simon Valentine because Simon has become aware of Conner’s secret identity. Unfortunately, Conner didn’t have time to deny Simon’s claim because Parasite appears out of nowhere and attacks them both. Parasite and Superboy tear up most of Main Street Smallville until Conner kicks Parasite into an abandoned wheat field. Superboy puts an end to Parasite by using his tactile telekinesis to manipulate the wheat grain as pummeling force to knock Parasite out. Superboy’s victory is short lived when Poison Ivy captures him with vines that are laced with kryptonite.

Conner tries to break free but Poison Ivy keeps him docile by showing him that she has Simon under her control. Ivy explains to Conner that she is trying to save Smallville because someone in Smallville is corrupting mother Earth but she needed Conner’s help and she knew Conner wouldn’t come willingly so she hired Parasite to subdue him. Conner laughs off her explanation because he has noticed the activity in Smallville. It turns out certain sections of town are being overrun by unusual vegetation. Leaving Ivy with no other choice, she seduces Conner with her pheromones thus making him a bit more compliant.

Krypto arrives on the scene and he remembers Ivy from their last encounter when Hush was ruining Batman’s life. Ivy asks Krypto to trust her and even though the situation didn’t smell right, he allowed Ivy to leave with Conner. Ivy tells Krypto to guard Parasite and protect Simon until they return. Krypto reluctantly agrees to her request. As soon as Ivy left with Conner, her hold over Simon began to fade. Simon takes this opportunity by extracting some of Parasite’s blood in order to discover weaknesses that Superboy may not be aware of and perhaps bend Parasite’s blood to his will.

Ivy and Conner arrive at a farmhouse that seems to be the epicenter of the peculiar greenery. Conner uses his x-ray vision to locate any signs of life while at the same time scoping out Ivy since her pheromones haven’t exactly worn off. Ivy notices Conner’s wanton stare and just as she was about to flirt with him, Conner spots a person that is hanging in the farmhouse. They discover old man Gilliam has a series of wires sticking out of his chest. Superboy follows the wires to a machine that is fitted with a timer which is set to go off in five minutes. Conner doesn’t know what to do because yanking out the wires might kill the old man or set off the device.

Ivy on the other hand, didn’t care about the old man so she ripped out the wires which caused the vegetation in one section of town to die off but the old man died from post traumatic shock. Ivy loses her control over Conner because his rage and moral perspective finally counter acted her pheromones. Ivy uses her kryptonite vines to take down Conner. Fortunately, Simon used Parasite’s blood on some of his experimental frogs. Their mucus like skin emitted the Parasite’s absorbing abilities and Simon controlled the frogs by via remote control. The Parasite frogs converged on Ivy and within seconds, Ivy fainted after being drained of her powers.

With Ivy down for the count, Superboy decides to destroy the machine but the machine’s timer reaches zero and everything within the farmhouse disappears. Conner carries Ivy back to Smallville while Simon heads back home with his newly enhanced amphibians. When Simon made his way back home, he notices a strange rock with ancient runes on it but before he could investigate further, he was scared off by a posse of weird looking farmers. 
When Smallville is attacked by a group of golems made of Smallville soil, Simon is one of the people who try to attack them. He uses a helmet allowing him to control a large group of exotically colored frogs which look like the villain Parasite..It's unknown if their coloring is important. 
At one point, Conner makes a new friend from the future who calls himself Psionic Lad. It turns out Psionic Lad comes from an alternate but possible future of Smallville where everything is bleak and horrifying. Smallville is ruled by a despot who calls himself the Prime Hunter. The Prime Hunter killed most of Psionic Lad's teammates but fortunately, Psionic Lad was set to the past to avert this terrifying future. Psionic Lad's teammates tell him to kill Simon Valentine before he becomes the Prime Hunter but Psionic Lad has his doubts since Superboy seems to bring out the best in Simon despite his jealously towards Conner in regards to Lori Luthor's affections.