- "GAH! Why?! Why?! WHY?! This CAN BE happening! I am the strongest being of the universe!"
- ―Kumon Kai after losing to Samuel Nakaoka the Second in the final time
Kumon Kai is the former leader of Team Baron and known as Kamen Rider Baron.
Battle from both Human and Inves WorldsEdit
The Bloody MomentsEdit
Having Samuel Nakaoka critically damages on his face and rips his right mouth, he screams loudly at Samuel Nakaoka who reveals his true natures of human and BEAST and he was the son of his predecessor and Reinzuya.
The Alternate TimelineEdit
The Bloody RevengeEdit
Ultra Monsters ArcEdit
Future World ArcEdit
Samuel Nakaoka and Kumon Rematch ArcEdit
Sun and Moon ArcEdit
Initially, he was very ruthless and harsh person like Reginald Kastle who became his Barian Mode alias Nash. He was shared his hatred towards Samuel Nakaoka who doesn't care about being a weaker than Reginald.
After permanently killed by Samuel Nakaoka who nearly kill Nagisa and corrupts the cities, Kumon completely became very insane and hatred towards Samuel Nakaoka and rampaging through the Depths of Inferno.
Lemon Energy ArmsEdit
Seiryuu Arms is the final form of Baron and true form of Lord Baron due to his redemption where Samuel Nakaoka was the best person.
Ate the rotten Golden Fruit, he viciously transforms into groteous stag-beetle-like monstrous form much as Samuel Nakaoka's great fury. He nearly beat Ryoma, Zack and Youko (who betrays him for being selfish kind), but only saved by White Wizard and Samuel Nakaoka the Second. His goal is to destroy and corrupt the cities as well creating the new images by taking Mai with him. However, his goal was stopped by an extremely enraged Samuel Nakaoka who using Formucar to transform into Formustar state by destroying him; ending his life eternally only Peter angrily tell him that his friends will permanently be a enemy of Samuel Nakaoka. Afterwards, his personality has became horror and insanity and towards Samuel Nakaoka the Second by attacking the Inferno.
This form is not techinally a final form due to considering to be monster form like Samuel Nakaoka the Second gains the "final form" (Formustar).
As in the alternate timeline that Kumon's horrific defeat of hands by Samuel Nakaoka and his critically injures, he renamed himself as Kaizer Baron who decided to want destroy Earth. Eventually, he was nearly killed by Samuel Nakaoka's HeatBlaze Drive Drill only he can enter Hell Destructor and fused into an moth-like hybrid monstrosity that can finally kill Samuel Nakaoka the Second once and for all. However, thanks to his alternate future wife Nagisa and Krim, he can transform into newly upgrade form, Formustar Dragostorm to fight and kill the monster, ending of Kumon's threats.
As before renamed himself as Kaizer Baron, his scars was extremely massive and unable to heal himself. His right arm was torn apart by HeatBlaze's Dead Saw Slash and face was almost destroyed. Because of the Primal T-Viral mutates him as punishment, he was unable to summon Inves and become weaker.
In the anime special of PR the Series: Sun and Moon, he summons Samuel Nakaoka's previous enemies.
Due to Samuel Nakaoka's mockery, he screams in rage and aggressively transformed into seemingly angered state. However, this form was still overwhelmed by HeatBlaze's powers.
Kaizer Baron HellEdit
The false god-like form fused with Hell Destructor's body and tries to kill Samuel Nakaoka the Second. However, he fails to defeat Samuel Nakaoka the Second and killed by Formustar Dragostorm Finish Drill Strike and Tridoron Full Color's Tire Exchange Drill.
- This Secondary Rider was only Rider that he turned evil, but cannot turned back into good because of his insanity in the this saga. After Samuel Nakaoka and Kumon rematch battle concluded,