Veldora Tempest

Veldora Tempest, also known as the Storm Dragon Veldora, is one of the most powerful beings in That Time I Got Reincarnated as a Slime anime — a True Dragon and a "Catastrophe-class" threat capable of immense destruction, controlling elements like wind, water, and space with devastating magic.

In his original dragon form (seen early in the series), he's portrayed as a massive, imposing blue-scaled dragon with black accents, radiating overwhelming aura and menace — the kind of existence feared as a natural disaster.

He's been sealed away for 300 years in a cave by a hero's Unlimited Imprisonment skill, leaving him incredibly bored and lonely until he encounters Rimuru Tempest (the protagonist slime). Impressed by Rimuru's attitude and intelligence, Veldora befriends him instantly, they make a pact, and Rimuru even gives him the family name "Tempest" (making him Veldora Tempest), symbolizing their brotherly bond.

Personality-wise, despite his terrifying power and reputation, Veldora is surprisingly childish, boastful, dramatic, and tsundere-like — he acts tough and arrogant at first but craves attention and companionship. After being freed and spending time with Rimuru (including absorbing manga/anime knowledge from him), he becomes even more playful, otaku-obsessed (especially with manga), comedic, and loyal to his friends, often providing comic relief through his over-the-top reactions and attempts to seem "cool" or refined.

Later in the anime (particularly from Season 2 onward), he gains a human form: a tall (over 2 meters), handsome, intimidating young man with blond hair, golden eyes, and distinctive black zigzag markings under his eyes and on his arms — though he can suppress his aura to appear less threatening.

Overall, he's Rimuru's first true friend and ally, adding a fun mix of overwhelming strength and goofy, endearing personality to the series.