|Game Debut||Danball Senki (PSP)|
|Anime Debut||Episode 01|
|Appears in||Game, Anime|
|Voice Actor||Hiroki Touchi|
|Relatives||Takeshi Hiyama (deceased)|
Mami Hiyama (alive)
|Occupation||Professor Yamano's Assistant (former)|
Bar Tender (outside cover)
Seeker Informative (former)
Veteran LBX Player
Leader of Innovator
|LBX:||G Rex (Break Over)|
Kabuto (temporary for Ban's training)
Ifreet (Break Over)
|Achievement(s)||Legendary LBX Player|
Ren Hiyama (檜山 蓮 Hiyama Ren), also known as 'Lex', is a supporting character to Ban and his friends in Danball Senki. In the first season's second half, it's revealed that he's the mastermind behind the Yoshimitsu Kaidou android, taking the Innovator's plans for his personal vengeance, making him the true main antagonist of the first season.
Lex has purple, spiky hair, brown eyes and is medium-sized. He wears a black fur coat, red pants, round golden red sunglasses and black shoes but he sometimes wears a black hoodie, with "Lex" in it and black sunglasses. When he's working at Blue Cats Coffee, his outfit's akin to that of a bartender, wearing a black apron, a red vest, black dress pants and a black bowtie.
For most of the series, Lex's a calm and supportive Seekers ally. However, during the finale, it's shown that he's hostile, arrogant and, aggressive and that he has a strong hatred for people, an outcome of his ethics.
Lex runs a coffee shop in Mysore called "Blue Cats Coffee". It seems that he's aware of the contents of the briefcase given to Ban, as well as his father's work within the LBX world. After Hanzou loses to Ban and his friends, it's revealed the two are working together, but Lex isn't worried that Hanzou doesn't have Achilles' frame.
Lex overwatches the battle between Ban and a brainwashed Kazu, only reacting as Achilles automatically activates V Mode. The next day, he invites Takuya over since one of his spies at Innovator confirmed that their next plan is to assassinate the Prime Minister. To have a fightning chance, Lex was given a box from a mysterious owner with a letter: "Borrow the strength of the children with the white LBX.". Realizing that the LBX was meant for Ban and his allies, he gives the tip to Takuya, who brings them to Blue Cats Coffee.
As Takuya’s explains Junichirou’s kidnapping, Ren assures the trio that Ban’s father wouldn’t have been harmed because the Innovators would still need him alive to assist their goals. He also warns them that the Innovators have power in the police, government, and several parts of the world. Later that night, he was unsure about telling them about Angel Star, and realized, alongside Takuya, that Tougorou Kamiya was involved and holding the professor hostage at Kamiya Craft.
On the outskirts of an industrial building near Kamiya Craft, he and Takuya look afar, considering that they wouldn’t be able to waltz in with heavy security. Lex commends Ban and friends on their boldness for infllitrating Kamiya Craft. After handing over his binoculars, he walks downstairs, stating that regardless of the situation, he will save them. After Ban, Kazuya and Ami defeat Ishideus, he arrives in a underground entrance to rescue them.
With Takuya’s help, he looks into the list of contestants for the next Angra Visdas to find their tournament mole. Lex's considered a legendary LBX player, a thing that was revealed to the main trio at the beginning of the tournament, hosted at the Blue Cats Coffee. Hanzou also reveals that the tablet he gave to Ban with the opponent's data came from him. After Ban emerging victorious from the tournament, Jin Kaidou gives Ban Professor Yamano's coordinates, where he was being held. Rina Ishimori returns with a plan to sneak into Kaidou's mansion and rescue the professor, which he and Takuya agree with.
He taught Ban an attack function that he could use in Artemis, a tournament which he also participated, alongside Hanzou. The two competed in the first round of Artemis’ A Block, where he let Hanzou take the lead. As Hakai-O defeats Zuul, Lex commands G Rex to uppercut the second opponent’s Gladiator causing a Break Over in one hit. The rest of the crowd shocks in awe at Rex’s legendary talents. The two eventually made it to the semi-finals. As Hanzou tells the others about wanting revenge against the Innovators for the Professor rescue mission, Lex immediately reprimands him for focusing on a petty objective to win and reminds Ban, despite his feelings towards Jin, that the Innovators’ deception shouldn't be underestimated. Jin uses Impact Kaiser to finish the match quickly, but, while Hanzou dodges, G Rex punches the ground, creating a shockwave that nullifies Jin’s attack. Following Hanzou and Jin’s clash, G Rex attacks Emperor M2 with Gatling Bullet, knocking it back. However, Jin recovers mid air and fires more missiles, but Hanzou protects G Rex from being damaged. Jin’s attack continues in one swing and, as Hakai-O breaks over, G Rex nearly hits Emperor M2 before apparently stopping. He loses as Emperor M2’s missiles finish off G Rex. After the fight, Jin asks why he suddenly stopped his attack, but he tells him that he was slightly better than him by a small margin. He leaves the stadium and calls an unknown person, telling them “Just as planned.”.
After Artemis, Lex appears to be absent for a good majority of the season. Despite this, he occasionally contacts Ban, Takuya and the Seekers. However, during the finale, it's revealed that he shot Yoshimitsu, replacing him with an android that would follow his commands. He proceeds with his plan, which was rewriting history by erradicating all world leaders, and heads to N City in Saturn, before being stopped by Ban, convincing Lex that there's still good in the world, making Lex rethink his actions and view of the world. Ultimately, Lex pushes Banto safety and commits suicide by remaining on Saturn as it self-destructs.
In episode 46 (W), it's explored Lex's Innovator set up, as he joined to take revenge against Kaidou and, the world and finding the professor, allowing his manipulations to run rampant before escaping Innovator and working with Takuya to create Seeker.
- "Humans are not beasts. Humans are not gods. Humans should question what is means to be human. Exactly what is "man" here for? Humans that have become too smart, and have started controlling and ruling the world, as if they were gods. Humans who obtain great power devour the weak and pay no mind to their acts of cruelty, as if they were beasts. At some point, those people who progressed too far forget what is like to be human. I wanted the world to think about this, about the way humans should be." - Lex's message to the world.