Seiya Ryuuguuin

"Ready Perfectly"

- Declaration of certainty.

Seiya Ryuuguuin is the main protagonist of the The Hero Is Overpowered but Overly Cautious series. He is the hero chosen by the goddess Ristarte and a hero renowned for his extreme cautions.

Appearance
"Be careful. Be cautious. Be overly cautious. You may find yourself alienated or hated, but you have to endure it all. This time, for sure, you'll prove that you can save your friends, your loved ones, and the entire world."

- Seiya's self-reminder

Seiya is a very tall and muscular young man with black eyes and black spiky and well-kept haircut which downturned and leans to his right, commonly seen covering his right eye. In the manga, his hair is more swept back, unkempt.

Seiya is almost always seen with a calm and pensive expression unless he is annoyed or angered and he is unanimously thought of as attractive by just about anyone he meets, even gods or enemies.

His outfit consists of a white undershirt, a black jacket and pants, and armor covering his crucial points such as his chest and joints. In the manga, his outfit is identical other than a belt over his waist and a different pair of shoes that are notably less medieval in appearance than his anime counterpart. He also has an extremely large set of bracelets that give resistances and stat boosts hidden from view under his jacket. They seem to weigh Seiya down but the resistances they give outweigh them for him.

When Seiya was first summoned, he was portrayed with much more casual and modern clothing.

Personality
Seiya is defined by his overly cautious nature who refuses to face any enemy he is not fully sure that he can defeat. He will attack defeated enemies repeatedly on the off chance that they can revive themselves, and trusts no one for they could be an enemy or carry a deadly illness.

However, his cautious nature also makes Seiya extremely diligent when it comes to preparing for future battles. He would grind for levels for days at a time and is almost tireless in his training.

Seiya also tends to speak bluntly to others and is quick to express his dissatisfaction with the opinions and actions of others. He seems rather inexperienced and ignorant of socialization, as he has been unable to spot other people's clear romantic feelings for him and has no trouble pouring holy water over strangers heads or picking hairs off Ristarte while she sleeps yet still is unaware of why these actions upset people.

Despite coming off as a person who does not care about anyone, his actions are driven by a want to avoid harm or death coming to those he cares about, even if it means pushing them away. In reality, he truly cares about both the people around him and the world he must save.

Seiya also seems to have no real hobbies or interests outside of things that will help him defeat his enemies. When confronted with things such as tasty food, celebration, or even sexual encounters, he is always dismissive and uninterested.

Despite his arrogance and harsh attitude he is actually a kind man and always try to protect his companion at all costs

History
"Gonna be okay."

- Seiya's recklessness

100 years ago, before being summoned to save Gaeabrande, Seiya was summoned by the goddess Ariadoa to save the B-ranked world of Ixphoria. During this time, Seiya was very reckless and dismissive of training, earning warnings from his fellow party members Princess Tiana and Colt, but nevertheless managed against all odds thrown to his parties. The series of victory had always held true for the heroes, and Seiya finally defeated the Demon Lord of Ixphoria after a struggling battle.

However, right when they were celebrating their victory, the demon lord attacked Colt from behind and pierced his chest with his tongue. The Lord revealed that it had two lives and the heroes only managed to take one before swallowing Ariadoa to regain his strength. Seiya, realizing Tiana and him were in no condition to fight, told Tiana to run away but the demon lord went after her first and revealed that she was carrying Seiya's unborn child. Cruelly, the demon then killed Tiana and the child in front of Seiya before killing him. After his destruction, Seiya lost all his memories about Ixphoria, but the pain and regret of not being able to save his loved ones were deeply carved into his soul.

Story
When Ristarte summoned Seiya to become a hero, he was initially extremely wary of the development and the goddess. When Rista asked him to say "Status", he instead said "Properties" and he saw a message from his past self, so he refused to begin his adventure right away and instead trained in his room for days.

When he finally did visit the S-Rank world of Gaeabrande, he immediately bought three sets of armor and items to help him escape from battle. Then he defeated a single slime by repeatedly, and unnecessarily, attacking it with his strongest techniques. However, this ends up drawing the attention of one of the Demon Lord (Gaeabrande)'s Four Heavenly Kings, Chaos Machina.

Seiya and Ristarte quickly flee from her and return to the Realm of the Gods. Here, Seiya begins training once again. He returns to Gaeabrande just before Maquina could kill another hostage, the father of a child he encountered earlier, and manages to defeat her augmented form.

After his victory, Seiya begins training with the sword god Cerceus but quickly becomes more powerful than the god. Then, he and Ristarte begin exploring more of the world, quickly discovering that a zombie army is approaching another village.

It is revealed that this army is summoned by the second heavenly king, Deathmagla. Seiya and Rista go to a church where Seiya kills a fake, zombie priest by pouring holy water over it. After this, he destroys the church to prevent the priest from being resurrected. This draws the attention of Mash and Elulu, who state that they will kill Deathmagla's army themselves. Before they even get the chance to come near the army however, Seiya destroys off the army with ease. After which he returns and meets with Elulu in an inn were Elulu states that Mash is gone. Moments later, Seiya, Rista, and Elulu receive a magic mirror by mail. The mirror is revealed to be a communication device where one can see and speak with whoever is on the receiving end. Deathmagla reveals himself on the other end and formally introduces himself. He threatens to kill Mash, whom he has captured and already visibly tortured. Seiya plots a plan in which he returns to the Divine Realm so that he can instantly reappear at Deathmagla's location. Having done so, Rista and Seiya come to face-to-face with Deathmagla. Deathmagla summons his most powerful monster, Dark Firus, to dispose of Seiya. While the monster is immune to most attacks, a certain sequence of attacks/magic can defeat it which Seiya takes advantage of to the surprise of everyone. After killing Dark Firus, Seiya kills Deathmagla and thus rescue Mash. Mash and Elulu then join Seiya as his equipment carriers

After this, Mash suggests Seiya and Rista go to Dragon Village because they have the only weapon that is capable to defeat demon lord.Hearing this Rista wants to go there as soon as possible but Seiya refuses and wants to go to Heavenly world instead. When arrived to heavenly World Seiya asks Cerceus to train Mash saying that as his bag carrier Mash has to become stronger, Cerceus using his scan skill on Mash and after he found out that Mash was weaker than him, he acts high and mighty just as what he did to Seiya when they meet for the first time. After leaving mash to Cerceus and Elulu to Hestiaca, Seiya wants to find gods or goddess to train him then he meets Valkyrie accidentally, Seiya asks her to train him and call her an exhibitionist much to Valkyrie's anger but then he saved by Aria and she introduce him to Adenela instead, fortunately, Adenela agree to train Seiya, in just 3 days of training Seiya was able to master Adenela's skill, Eternal Sword. Before Seiya goes to dragon cave Adenela said that she wants to give something for him, Unbeknownst to Seiya and co. Adenela meets them dressed up beautifully and bring cake, Rista notice Adenela really fall in love with Seiya but he just brushes it off and rejects her make Adenela cry blood and make a ruckus at heavenly World.

Ristarte
The first time they met was when the goddess Rista summoned him, she is strongly attracted to Seiya but is sometimes annoyed by his cold, abrasive personality. Seiya does not reciprocate these feelings at first, and he often ridicules her role as a goddess. He often picks some of her hair lying around to make monster-slaying swords using his Synthesis skill, to her annoyance. Despite this, Seiya shows moments of deep caring for her, as he told the citizens of Dragon Village that he only eats her cooking, leaving her touched. When saving Elulu from sacrificing herself to become a sword, Rista was proud to have chosen her hero Seiya to save the world.

It is revealed that Rista, going by the name Tiana, was engaged to Seiya in a previous world called Ixphoria. Back then, Seiya was much more carefree and happy-go-lucky. Rista was also pregnant with Seiya's child. However, they were all killed by the demon lord, so this had a lasting impact on Seiya's unconsciousness that would make him more cautious and calculating in the future.

After Rista summons Seiya a second time (with the help of Ishtar's blessing), Seiya is considerably kinder to Ristarte, acknowledging his feelings for her and even allowing her to be physically affectionate towards him to a certain extent. Nevertheless, he is still overcautious and harsh, but this is because he is deeply concerned for her safety during their mission in Ixphoria.

Ariadoa
Ariadoa is often amused by Seiya, especially his defiant attitude to the other Gods. She does not seem to have affection for him, though she does care for him. Seiya in turn does not show her the same hostility he shows other gods, though he doesn’t thank her for defending him from them.

Ariadoa is aware of his past life, as she summoned him to be the hero there before he and his party were killed. She feels strong guilt for what happened in the past, so she tries to help Seiya whenever he needed training. She introduces Seiya to gods that can help him with his training, such as Cerceus and Adenela.

Valkyrie
Seiya believes Valkyrie to be an exhibitionist and masochist and outright demanded she trains him. In response to his disrespect, she was hostile towards Seiya, but they form a mutual respect after she learnt of his plan to save Gaebrande and taught him Destruction techniques like Valhalla's Gate.

Mash
At first, Seiya was quite disrespectful towards Mash, not bothering to remember his name. However, it was shown that he does care for the young hero when he saved him. Though he still didn't allow Mash to fight, referring to him as his bag carrier rather than a teammate. Before death, Seiya told Mash what he truly thought of him, and encouraged him to be a great warrior.

Elulu
Seiya first thought of Elulu as weak, as her and Mash's level was way lower than his. As a result, he didn't care to remember the two. Elulu seemed more tolerant towards Seiya compared to Mash and as such referred to him in a more polite manner. Even when Elulu's power was unsealed, Seiya was protective of her and didn't allow her to engage in combat, also showing this side when he saved her from becoming the sword that would slay the Demon King. Before death, Seiya expressed how much he cared for her and Mash.

Adenela
Seiya trained under Adenela to learn her skills, though was unaware about her growing affections towards him. After he finished training, he unknowingly caused Adenela to change into a happy, cheerful person. When she confessed her love to him, he rejected her coldly, causing her to go insane. He used her affection against her to stop her from killing him and in helping him in trying to kill the Reaper, though he was not surprised when she failed.

Cerceus
Seiya trained under Cerceus to learn his swordplay, showing initial disrespect towards him. Seiya's training regime was too hard for Cerceus to handle, and he started to become terrified by Seiya, so much that he became scared to wield a sword. Seiya continued to force more training out of him until Ristarte told him to stop. Seiya thinks very little of Cerceus, as he is one of the only gods he does not respect.

Rosalie Roseguard
At first, the two mutually disliked each other, their personalities being polar opposites. Seiya thought of Rosalie as a bad leader, being too brash and arrogant. Seiya called her dog-like when she got angry and would slap her when she tried to hit him. He still had respect for her, however, telling her to lead the kingdom after her father died. After his death, Rosalie called him a true hero.

Powers and Abilities
Seiya's main strength comes from his extremely cautious nature. Due to his nature, he thinks of almost any possibility and scenario a potential enemy can come up with, allowing him to prepare for almost anything. Another great strength of Seiya is that he is immensely good at learning new techniques to defeat his enemy. Besides this, he has trained himself up until peak condition. He is an immensely fast, durable, strong, and skilled sword fighter. Despite this, Seiya can still be harmed, this is especially the case in an opponent who has higher stats than himself. Because he learned Valhalla Gate he has the potential to kill any enemy, albeit at the cost of his own life. Seiya has an 'EXP boost' ability which allows him to level up quicker.

Skills
Seiya has many skills in his arsenal, and is quite a fast learner. Unfortunately after Seiya goes back to his world and is summoned again, his level goes back to 1 and so his stats and all of his skills are lost with the exception of Valkyrja Techniques and Berserk State which were carved into his soul.
 * Atomic Split Slash
 * Fire Magic
 * Hell's Fire
 * Maximum Inferno
 * Automatic Phoenix
 * Automatic Phoenix Infinity
 * Phoenix Drive
 * Phoenix Thrust
 * Phoenix Spear : Combination of fire magic and spear skill. Seiya can make hundreds of spear made of fire to strike his opponents. This attack was proven to be so powerful as it can intercept one of Demon King Ultimaeus' attack.
 * Flight : An ability that allows Seiya to fly.
 * Wind Blade
 * Double Wind Blade
 * Synthesis
 * Meteor Strike : Seiya summons a small meteorite to crush his enemies, this technique is very powerful since it can kill more than 9000 undead in one strike however Seiya needs to concentrate to use this skill properly.
 * Dimension Blade : A photon blade that can cut through space.
 * Oscillatory Wave
 * Eternal Sword
 * Eternal Sword EX
 * Double Eternal Sword
 * Double Eternal Sword EX
 * Shining Arrow : A skill he learn from Mitis the Goddess of Archery. With this skill, Seiya can make an arrow of light to strike his opponent, Seiya is very proficient with this skill since he can bypass his limit and be on par with the Goddess of Archery's limits of seven consecutive shots(Seven Shot Shining Arrow).
 * Three Shot Shining Arrow
 * Five Shot Shining Arrow
 * Seven Shot Shining Arrow
 * Boomerang Birdie Boom Boom : A technique Seiya came up with as a precaution in case that the Seven Shot Shining Arrow misses its target. If the Shining Arrow missed, it will transform into a light attribute magical bird and hunt the enemy down.
 * Valkryja Techniques
 * First Valkryja : Shattered Break
 * Fourth Valkryja : Astral Break
 * Astral Break Revised
 * Fifth Valkyrja : Shadow Break
 * Seventh Valkyrja : Permission Break
 * Ninth Valkryja : Counter Break
 * Omega Valkryja : Valhalla Gate
 * Valhalla Gate Another
 * Appraise
 * Earth Magic
 * Earth Serpent
 * Cave Along
 * Clear Ceiling
 * Ground Penetration
 * Earth Golem
 * Great Iron Wall 
 * Repair Iron Wall
 * Clear Wall
 * Iron Dome
 * Bomb Boulder
 * Endless Fall
 * Transform Automatic Naga
 * Slithering Mine


 * Jolly Piper Skills
 * Resilient Lungs
 * Burst Air
 * Sustained Fluting
 * Modest Flute


 * Art of Change
 * Transform Target
 * Hexagram Ritual of Retribution
 * Berserk State : A skill he learns from the Goddess of War Zet. With this skill, Seiya can increase his stats but he can't use another skill, however after he grasped this skill he can figure out how to use another skill.
 * Valkyrja Explosion: Crimson Boom
 * Double Crimson Boom
 * Bombing Crimson Prison
 * Drain Charge Attack : A technique that Reckless Seiya was supposed to use against Demon Lord Ultimaeus in order to beat him. This technique was learned by Cautious Seiya from the Reckless Seiya inside of Death Emperor Sirrusht's illusion. Ironically enough, Cautious Seiya didn't use this attack on his battle against Ultimaeus.
 * Resume Drain Charge Attack
 * Class Change
 * Instant Change
 * Ghost Bites
 * Ghostbuster Overdrive
 * Divination
 * Wind Magic 
 * Wind Shield
 * Lightning Magic
 * Thunder Strike
 * Anti Clock Field: A skill Seiya got after training with the Supreme Goddess of Time Chronoa. With this skill, he can prevent his enemies for manipulating time.
 * Converse
 * Ice Magic
 * Fenrir Shot
 * Fenrir Beat 
 * Invisibility
 * Mimicry: A unique and very useful skill he learns from Joker. With this skill, Seiya can mimic or copy someone skills perfectly even from a powerful individual such as Lucifer Crow the Legendary Demon, at first Seiya need to use 1/3 of his total MP to activate this skill and can maintain it for several seconds but after the extensive training he just needs to use 1/15 from total MP and can maintain it for 3 minutes.
 * Info Shared
 * Darkness Techniques
 * Dark Hand
 * Infect Lover
 * Cage of Purge
 * Lasting Ray

Stats (Gaeabrande)

 * -| Level 1=


 * -| Level 15=


 * -| Level 37=


 * -| Level 99=

Stats (Ixphoria)

 * -| Level 51=


 * -| Level 99=


 * -| Berserk State: Phase 1=


 * -| Berserk State: Phase 2=

Etymology

 * The name Seiya means "holy" (聖) (sei) and "man" (哉) (ya).
 * Seiya's surname Ryuuguuin means "dragon" (竜) (ryuu), "temple, shrine, palace" (宮) (gu) and "hospital" (院) (in).

Trivia

 * Seiya has consistently been proven to be right in his caution multiple times throughout the series.
 * Seiya's outfit appears to just be armor pieces placed over the clothes he was summoned in.
 * Seiya makes a cameo appearance in the comedy cartoon series Isekai Quartet 2, alongside Ristarte.
 * In his original world, Seiya has a job that allows him to wear bulletproof vests.
 * Aside from his death in his past life, Seiya has yet to be defeated by any enemy he has encountered.
 * However, it should be noted that he did have to sacrifice himself to beat the Demon Lord (Gaeabrande).