Veldora Tempest

Veldora Tempest (ヴェルドラ゠テンペスト), also known as Storm Dragon Veldora (暴風竜ヴェルドラ) is one of five True Dragons.

Human form
After being released from Rimuru's stomach, Veldora was gifted one of his Body Doubles as a vessel to incarnate within, which Veldora reshaped to his liking. He has blond hair, and is over two meters tall. Veldora's alterations to the body turned the face masculine, though Rimuru's general facial features remained. As Veldora learned to suppress his tremendous aura before leaving the Sealed Cave, he appears to most people as merely a handsome, albeit slightly intimidating, young man.

Dragon form
His gigantic body is covered in black steel like scales, with his wings and underside taking on a bluish color. His eyes are deep golden and the back of his head is covered with four horns extending backwards.

Personality
Veldora is generally boisterous, excitable, but also fairly easy going. Despite his reputation as someone who just wants to rampage, Veldora is largely only dangerous if he doesn't get to unwind once in a while or if his loved ones are threatened. He is also quite energetic, prideful, and has no reservation in showing off his strength. Veldora is rather shy and socially awkward but hides it behind boasts of how "great" he is. He also has no social tact, seeming to not understand a simple request from him is enough to intimidate anyone into compliance regardless of their own personal feelings. Aside from his childish nature, he is quite knowledgeable about many things and has an unquenchable curiosity at his core. Veldora tends to act meek if things don't go his way, resulting in people wondering if Veldora is really as terrifying as the legends say.

After meeting Rimuru and reading the manga stored in his memories, which he refers to as "sacred texts", he began to reconsider some of his more destructive previous behavior. His time spent in Rimuru's stomach with Ifrit and his time spent living in Tempest resulted in Veldora developing a somewhat more patient, analytical, and less impulsive personality.

Despite his nonchalant personality, he greatly appreciates Rimuru as his sworn friend and trusts him. Because the lowly slime cured the loneliness and boredom afflicting him, Veldora feels incredibly proud to have met Rimuru. In Veldora's eyes, Rimuru is an equal despite being a fledgling monster in a new world; Veldora understands and even motivates Rimuru to bring more types of entertainment to the world, because since meeting Rimuru, his life has become filled with family, friends, and new ways to entertain himself.

Veldora is not good at confronting his sisters, believing they viewed him as their plaything, tormenting him and causing deep emotional trauma. He seems to hold high respect for his older brother, Veldanava, who shielded him from his sisters. He was the youngest True Dragon until Rimuru's ascension, which is ironic considering that Rimuru behaves more like a mature brother than Veldora, even standing up for him against his sisters. To all others, Rimuru appears to have "tamed" Veldora, which is not exactly untrue.

Background
He was born as the incarnation of chaos, having control of wind, water and space. He was the fourth to emerge as a True Dragon among his siblings. From the moment of his birth, Veldora has been plagued by a relentless sense of restlessness, which often leads him to embark on destructive rampages often manifesting in violent storms. His boredom compels him to seek out challenges from his elder sisters, Velzard and Velgrynd, in order to assert his superiority. However, this cycle of reincarnation and rivalry has left an indelible mark on Veldora, instilling within him a perpetual fear of his formidable sisters that persists to this day.

One day, 2000 years ago Veldora went and trashed a vampire city ruled by Demon Lord Luminous Valentine to relieve his boredom, making him bear the grudges of the Queen of Nightmares since.

When the Eastern Empire dispatched an Army to expand their territories 300 years ago, they encountered Veldora in Jura Forest and got crushed. Because of that, a Hero was dispatched to defeat him. The Hero imprisoned him with her Infinity Prison as a result, sentencing him to live his days in monotonous boredom.

One fateful day, a slime bumped into him. Curious, as nothing should be able to get close to him due to his large pool of magical energy, he started to converse with the small slime.

After befriending Rimuru, Veldora consented to Rimuru's plan to store Veldora in his stomach while he worked on finding a way to release Veldora from the Infinty Prison. Veldora ultimately spent a year inside Rimuru's stomach, passing the time by going through Rimuru's memories of his previous life in Japan. He attempted to gather the souls of others that Rimuru consumed into the stomach with him, resulting in Ifrit joining Veldora. Ifrit and Veldora forged a strong friendship during their time spent in Rimuru's stomach, and Ifrit eventually agreed to become Veldora's apprentice.

Veldora was unleashed on the unsuspecting world after Great Sage evolved into Raphael. Raphael boosted Veldora's Investigator skill to 345 times its previous speed. Then, at Raphael's urging, Veldora upgraded the Unique Skill Investigator to the Ultimate Skill Faust, further boosting Veldora's processing power by a thousand times. These upgrades allowed Veldora and Raphael to finish the process of freeing Veldora's astral body from the Ultimate Imprisonment technique.

Veldora currently inhabits one of Rimuru's clones as his own form, and a Soul Corridor with Rimuru allows the two to share their powers with one another. Thanks to storing his memories within Rimuru, Veldora is functionally immortal. So long as Rimuru lives, Veldora can be summoned again regardless of how much damage he takes.

Trivia

 * He is one of a handful of individuals aware of Ciel's existence, along with Velgrynd, Charys, Mjurran, Benimaru, Diablo, Grucius, Chloe, and Rimuru himself. Benimaru, Diablo, and Grucius are only aware of Raphael's existence in the manga continuity.
 * To the surprise of many, he is quite capable as a cook, working a Takoyaki stand during the festival and even amazing people with how good they were.