Eric Tyson

"If there is a hand reaching for help, and I don't reach out my hand when I can. The regret would make me wish I were dead... I reach out my hand, because I don't want that"

- Eric Tyson

Eric Tyson is Power Rider. He is the main protagonist and one of the main characters in Power Rider. Before Eric Tyson, there was a previous Power Rider who had fought & sealed the Greeedemons away.

Past
Eric Tyson was the son of a politician who traveled the world with his grandfather. During one of his expeditions, he traveled in Africa. During his time in Africa, Eric attempted to use his fortune to help out a village. In turn, Eric befriends a girl named Alfreed. Following her to her village & learning the residents as well as their culture, he is dragged into a civil war between villages. As it turns out, Cain (Alfreed's brother), became an assassin for an enemy tribe in order to survive. During the tragic moments of the civil war, Alfreed is presumably killed in the war & Eric is held captive for ransom. However, his family only paid for his ransom, allowing him to escape Africa. However, his family used his tragedy to get the people's support. Though Eric ultimately refers to this moment as his greatest regret, the ordeal caused Eric to lose any selfish desire & become willing to help those in need, going so far to even risking his life for complete strangers.

Power Rider
He returned to the United States to fund for more of his travels. His latest part-time job, a security guard at the Ness Art Museum, ends due to the destruction of the museum around him due to him being drugged to sleep by some would-be robbers. Eric takes a strange red coin he found while off duty which he thinks is his pay. This causes a disembodied arm to begin to follow him around, until the arm announces that it is called Blazephyr & is one of the ancient beings known as the Greedemons, & he needs Eric's help to become King. When they are attacked by a monster called a Yummy, Eric risks his life to rescue Blazephyr, who in return saves him & gives Eric two more strange coins, calling them "Power Coins", & a belt, enabling Eric to transform into the Power Rider.

After destroying the Yummy & further encounters with the Greedemons, people from the Ness Foundation begin to approach Eric, offering their assistance in the fight against the Greedemons & Yummy, but their true motives are not clear. He also gets a job & housing at the Cous Coussier, after the owner Chiyoko Shiraishi finds out that he is a world traveler. In the process, joined by Akira Date, Eric learns more of the Greedemon's desire to become whole and the reason why Ankh is unable to assume his complete form. However, things changed when Eric ended up becoming a host to half of a set of Purple Core Medals that react to his lack of selfish desires, the same presumed reason why he is able to use Power Rider's powers without any sign of going berserk so far like the First Power Rider, with dangerous consequences. Soon after, Eric learns from Kousei Kougami, the Foundation's owner, that the only way to counteract the purple Core Medals is to acquire a desire of his own, something he is yet capable of.

Later on, he turns into the dinosaur-like Eric Greeed after absorbing two more purple Core Medals from the other Purple Greeed, Kiyoto Maki, in a bid to make him go beserk. However, it was by then Eric remembers his desire is to have the power to help others and later agrees to Kougami's suggestion to absorb all the Cell Medals in the Kougami Foundation's possession to achieve that desire. However, it does not halt Eric's Greedification during his his final battle when he uses all the Cell Medals in his body in a risky attack that fails to destroy Maki. But before Eric undergoes his Greeed transformation, Ankh gives Eric his last three Core Medals, disappearing from Shingo and allowing Eric to transform to defeat Maki, resulting in the disappearance of the Core Medals, with the Core Medal that houses Ankh's consciousness splitting in half.

As a now-normal Eric falls back to the Earth, Ankh appears to him as his disembodied arm, bidding his farewells, before disappearing into half of the broken Taka Medal that once held his consciousness. Saved by Kamen Rider Birth, receiving the other half of Ankh's Core Medal that Hina found, Eric leaves Japan and resumes his journey around the world, using Ankh's/Shingo's iPhone to keep in touch with his friends while trying to find a way to fix the broken Taka Medal with a spectral Ankh arm following him.

Movie War Mega Max
Eiji returns to Japan as he sees Ankh waiting for him in the airport, curious as he still holds Ankh's broken Taka Core Medal. Appearing to aid Date and Goto, he regains several of his Core Medals from Kamen Rider Poseidon, allowing him to trade blows with Poseidon until he realizes that Poseidon's host, Michal, is suffering. After meeting Michal, Eiji is able to separate the Poseidon entity from Michal. Giving advice to Michal, Michal regains the courage to assume his original form as Kamen Rider Aqua. Together, Eiji and Michal defeat Poseidon. Eiji gives his farewell to Ankh, realizing that he's from the future, but is reassured that he will resurrect Ankh one day. A moment later, Foundation X attacks Eiji, taking Poseidon's Core Medals. Recruiting Gentaro from the Kamen Rider Club, he meets up with Shotaro and Philip, explaining what Foundation X is after. Along with Gentaro, the two free the Seven Legendary Riders as Eiji and Gentaro runs to the Exodus. Meeting with Kamen Rider Aqua once again, Eiji receives the Super Core Medals, effectively transforming into the Super Tatoba Combo. Together with Fourze, the two defeat the Super Galaxy King and Eiji resumes his journey of restoring Ankh's Taka Core Medal.

Kamen Rider OOO (novel)
In the aftermath of Mega Max, Eiji returns to Africa to stop the still ongoing civil war. Using the OOO Driver, he uses the Tatoba Combo as a diversion to draw fire, uses the Gatakiriba Combo to destroy the soldiers' guns, uses the Latorartar Combo to destroy tanks, and uses the Sagohzo Combo to stop rocket launchers. Using the Tajadol Combo, Eiji wipes out the air forces while rescuing the pilots from their deaths. In the dried out deserts, Eiji uses the Shauta Combo in order to create rain. The enemy tribe slowly starts to fall back with Eiji's intervention and the war slowly ends.

Super Hero Taisen
During Super Hero Taisen, Eiji is attacked by the Dai-Zangyack army and is sent to the Dark Dimension. Eiji later reappears teaming up with the Gokaigers, lending them his Core Medals, which turned into Ranger keys. Joe refers to this as OOO's Grand Power.

Movie War Ultimatum
When Koyomi came under attack by Ghouls after all the Riders entered Yu Kamimura's Underworld, Eiji appears and fights them off. Explaining that Gentaro called for help, he explains that Riders should always do what they can to help each other out. This makes Koyomi's Please Ring glow, and within the Underworld, projections of Eiji (along with Shotaro, Phillip, Ryu, and Goto) giving the kids Rider Rings. Touching the Rings on Haruto's belt casts a spell that summons Eiji and the other Riders, giving Wizard and Fourze support as they defeat the Akumaizers.

Kamen Rider Wizard
OOO appears with all the Heisei Riders from Kuuga to Fourze, led by Decade, in a special two-parter after the finale, The Kamen Rider Rings, and Neverending Story.

War of the Riders: Masked vs. Kamen vs. Power
OOO joins the Heisei Riders in their war with the Showa Riders in Zawame City.

At the climax, OOO is one of the surviving Riders in the battle between Heisei and Showa. He attempts to perform his Tatoba Kick on Riderman, but is defeated by his Rope Arm, transforming into his Lockseed. Gaim is soon left as the last Rider standing before Ambassador Darkness of the Badan Empire reveals himself to be Ryo Murasame (Kamen Rider ZX). Together, they restore the other Riders and all 30 Kamen Riders defeat the Badan Empire.

Personality
Despite often coming off as happy-go-lucky in his personality, Eiji is actually quite strong-willed and was easily able to pick up on the fact he could use Ankh's need for him and the OOO Driver to keep the Greeed in line. Another defining trait is Eiji will fight to protect anyone in need, even complete strangers and at the risk of his own life. This stemmed after his regret from not saving the little African girl he befriended during a civil war which his family fortune started. He keeps a collection of coins and almost always has pairs of underwear of different designs and colors which he at times even gives to others. This is revealed to stem from an optimistic outlook thought to him by his grandfather, who said that all a man needs is a pair of underpants for tomorrow. Eiji possesses no selfish desires which made him ideal for being OOO but also became a weakness once the Purple Core Medals sought out a host, as they immediately found him and took root. However, taking the advice of Akira Date, after becoming a Greeed, Eiji remembers the desire he had so long ago; Eiji wanted the power to protect people no matter where they are, which Ankh gave to him in the form of the OOO Driver.

Devices

 * OOO Driver: Transformation belt
 * O Scanner: A device that scans the medals
 * O Medals
 * Core Medals: Allow OOO to use Combos
 * Cell Medals: Uses for weapons and the Ride Vendor
 * O Medal Holder: A case that holds the O Medals
 * Candroids: OOO can-like support robots

Weapons

 * Medajalibur: Personal weapon
 * Taja Spinner: Tajadol Combo's primary weapon
 * Medagabryu: Putotyra Combo's primary weapon
 * Burahngi: Burakawani Combo's flute

Vehicle

 * Ride Vendor: OOO's Rider Machine
 * Toride Vendor: Latorartar Combo's personal bike

Ranger Keys

 * see also: 

The Kamen Rider OOO Ranger Keys appeared when Eiji gave his OOO Medals to the Gokaigers, transforming them into these keys. In Super Hero Taisen, these keys changed the Gokaigers into OOO's Full Combos, and were then used to power the GokaiGalleon Buster.
 * Gatakiriba Combo Key
 * Latorartar Combo Key (ライトラーターコンボ キー)
 * Sagohzo Combo Key (サゴーゾコンボ キー)
 * Shauta Combo Key (仮面ライダーオーズシャウタコンボ キー)
 * Tajadol Combo Key (タジャドルコンボ キー)
 * Putotyra Combo Key (プトティラコンボ キー)

Gokaiger/OOO 

Tatoba Combo
OOO Lockseed (オーズロックシード): Allows Kamen Rider Baron to transform into OOO Arms, equipped with the Medajalibur. The core image depicts the OOO Driver while the lid backside image depicts the Taka Medal. Also a Gridon-styled Lockseed in the toyline.
 * Transformation: OOO Arms: Tatoba, Ta~To~Ba!
 * Squash: Scanning Charge (スキャニングチャージ)
 * Au Lait: Seiya (セイヤ)
 * Sparking: Combo Change (コンボェンジ)

Tajadol Combo
OOO Tajadol Combo Lockseed (オーズタジャドルコンボロックシード): The core image depicts the OOO Driver while the lid backside image depicts Ankh's three Core Medals: Taka, Kujaku, and Condor. Baron/Gridon-styled Lockseed. When activated, this Lockseed announces "Tajadol" (タジャドル).
 * Transformation: OOO Arms: Ta~Ja, Ta~Ja~Dol!
 * Squash: Taka Squash (鷹スカッシュ)
 * Au Lait: Kujaku Au Lait (孔雀オーレ)
 * Sparking: Condor Sparking (コンドル スパーキング)

Putotyra Combo
OOO Putotyra Combo Lockseed (オーズプトティラコンボロックシード): The core image depicts the OOO Driver while the lid backside image depicts the three Purple Core Medals: Ptera, Tricera, and Tyranno. Baron/Gridon-styled Lockseed. When activated, this Lockseed announces "Putotyra" (プトティラ).
 * Transformation: OOO Arms: Pu-To-Tyranno~Sau~rus!
 * Squash: Gokkun (ゴックン)
 * Au Lait: Ptera, Tricera, Tyranno (プテラ, トリケラ, ティラノ)
 * Sparking: Putotyranno Hissatsu (プトティラノヒッサツ)