|“||My companions died trying to bring peace to this world. I want to fight to make sure they didn't die in vain.||”|
—Ren, Volume 11, Epilogue
He was less inclined to treat the Shield Hero unfairly compared to the other two legendary heroes, however, he is terrible with cooperating with others and his solo player tendencies caused frequent problems.
He was deceived by Malty which caused him to unlock the curse series of Greed and Gluttony at the cost of going rogue and berserk. He was brought to his senses after his duel with Eclair and promised to earnestly help save the world.
Ren has short black hair that falls flat on his head and kind blue eyes previously looking cold and distant. He was described to suit the role of the protagonist of dimensional-cross stories from bishounen manga and anime.
He primarily wears simple clothing consisting of light clothing underneath and darker clothing on his exterior. When traveling he seems to bring a simple breastplate attached with a blue cape.
In the past, he wore a dark overcoat with dark armor plating placed on his chest, right shoulder, and lower areas of his legs. Additionally, he wears dark leather gloves, boots, and a dark blue scarf draped around his neck
The weapon in his possession is the Legendary Sword which was granted to him when he was summoned to another world.
Ren is a person who acts cool and tries very hard to portray a loner's image. He runs his party like a guild, only working with the other members when the prey he seeks to kill is too strong for him to hunt alone. His attitude towards his comrades is that weaker members should work to individually increase their powers to catch up to the stronger ones.
Like the other heroes, Naofumi Iwatani excluded, he is initially under the impression that the world they've come into is a game, and he stubbornly refuses to think otherwise. Unlike Motoyasu Kitamura and Itsuki Kawasumi, Ren seems to actually recognize to some extent the consequences of his actions, as he understood it was his fault that the Zombie Dragon caused a plague. He is also more reasonable than Itsuki or Motoyasu, as he believed in the possibility that Naofumi was telling the truth when he claimed that Melty Q Melromarc was under his protection and not his hostage, and tried to propose an idea that would help resolve the situation peacefully. He, alongside Itsuki, also stood up for Naofumi after Malty and Motoyasu tried to take Raphtalia from him via cheating, and called Motoyasu out for believing Raphtalia was brainwashed even when they saw her comforting an obviously deeply upset Naofumi.
However, like Motoyasu and Itsuki, Ren started becoming more arrogant about his ability. He would refuse to acknowledge his defeats or admit the reason for them was because he wasn't as strong as he claimed he was. Instead, he would fault others around him while trying to act superior, ironically making himself look weaker as a result. This grew more noticeable when he and the other heroes were told they needed to start training seriously, as he tried to dismiss the training as pointless and a waste of their time, believing they were better off getting stronger by leveling up, missing the whole point of why they need to get stronger. Even when Eclair Seaetto overwhelmingly defeated him during their sword match to prove him wrong, he resorted to using a skill out of desperation and still tried to deny the fact that he was clearing losing, ironically proving her right.
Ren grew increasingly more unstable following his defeat and the death of his companions by the Spirit Tortoise. He refused to admit that it was his recklessness and arrogance that got his companions killed by saying they were weaker than he expected, as well as the sudden change of the people's treatment of him only further this. This made it easier for Bitch to trick him into believing her while making Ren think Naofumi, the Queen, and Motoyasu were the evil ones. This proved to be a huge mistake that cost him everything he had when Bitch betrayed him by the next morning, which triggered Ren's Curse Series.
Following being possessed by the Greed Series, Ren began stealing from others like how people stole from him. But at the same time, he didn't want to reveal his identity, so he began wearing a mask and working from behind the scene, forming his own band of bandits to attack people. He also grew more contradict; he acted more prideful and boastful than before but would usually attack his targets when they were alone. He grew even worse after succumbing to Gluttony, becoming more violent and obsessed with increasing his power by killing people and stealing their EXP points.
After being freed from the cursed weapon's influence, he officially joins Naofumi as a friend and ally He manages to mellow out and accept his faults; taking responsibility for his past mistakes while also striving to become stronger the right way by becoming Eclair's student. Because of this he gave up on his cool guy persona and has become much more genial.
Ren comes from an alternate Japan. In the world he lives in, everything is much more advanced and futuristic. In his world, every game in the modern era is run on VRMMO.
One day while on the way home from school, Ren was caught up in a murder case. The murder case was pretty well known around the town he lived in. Ren mentioned how he remembers saving his best friend and how the criminal was arrested. Ren didn't go into too much detail after that, but started rubbing his side when talking; it was suspected that Ren was probably stabbed on the side of his body during the struggle then later died from blood loss. Before he knew it, he woke up he found himself summoned to another world. The world reminded him of a lot of the VRMMO he played in the previous world, Brave Star Online.
- The name Ren means "tempering, refine, drill, train, polish" (錬).
- Ren's surname Amaki means "heaven, sky" (天) (ama) and "tree, wood" (木) (ki).
- The Four Legendary Heroes are all inspired by the protagonist of other series the Author has read before in the past.
- The character trope that Ren is based on is the generic isekai protagonist.
- His physical traits are; black hair, dark clothing, and sword wielder.
- His personality traits are; cool, loner, and solo-player.
- His background traits are; living in a world where VRRMOs exist and play a game title "Brave Star Online."
- The Fandom tends to compare him to the protagonist of Sword Art Online; Kirito, who ironically shares many of the above traits and the same Japanese Voice Actor.
- Because of Ren's solo-player tendencies, he treats his party member as NPC and uses them to grind in appropriate leveling grounds in accordance with their levels and will join hand only when needed.
- In the manga it's shown that Ren can not swim and will drown in even shallow water.