Grymwelte is a character from the Japanese manga and anime series Ragna Crimson, where he serves as a minor antagonist. He is a member of the Winged Bloodline, one of the powerful dragon families in the series, holding the rank of the tenth seat among the superior dragons within that bloodline. Despite being a superior dragon, his rank indicates that he is among the lowest in the hierarchy of that elite group, a fact he himself acknowledges. Within his bloodline, he is considered young, and as such, he has not yet fully unlocked his latent potential.

In terms of his magical abilities, Grymwelte is known as an enhancement sorcerer and is referred to as the Black Dragon Sorcerer. His primary form of magic is a strengthening expression, which is a simple but potent ability that increases the numerical value of a target's properties, such as making an object harder or flames burn larger. A distinctive characteristic of this magic is that the more it is used on a target, the darker that target becomes in color. For direct combat, Grymwelte can use his own blood to generate flames and create black, razor-sharp tentacles to attack his enemies. He typically appears in a human-like form, that of a robust middle-aged man, but possesses the ability to transform into a full dragon, which brings out his complete power. In his private life, a minor detail notes that he has a preference for being nude.

Grymwelte’s role in the story is central to the inciting incident of the series. Acting under the orders of the Dragon God and his superior within the Winged Bloodline, Ultimatia, he is tasked with leading an attack on the Reze Kingdom. His target is the city of Ronabera, where the protagonists Ragna and Leonica reside. In the original, unaltered timeline, Grymwelte is directly responsible for the fall of Ronabera and for killing Leonica as she tries to protect Ragna. This tragic event sets the stage for the story's core conflict.

However, the narrative seen in the series takes place in a revised timeline. Here, a future version of Ragna merges with his past self, granting him memories and immense power in the form of Silver Aura Martial Arts. When Grymwelte attacks Ronabera in this new timeline, he confronts this empowered Ragna. Grymwelte’s personality is defined by his ruthlessness and bloodthirsty nature, as he takes great pleasure in looking down upon and massacring humans he considers inferior. Yet, when faced with Ragna’s overwhelming silver aura, his arrogance turns to fear. He expresses furious disbelief that a mere human could cause him such terror. His brief moment of panic leads him to transform into his dragon form, but the transformation is futile. Ragna freezes and destroys Grymwelte almost instantly, saving Leonica and drastically altering the future. His defeat occurs very early in the story, marking him as a character whose primary function is to demonstrate the immense power gap that Ragna has now crossed and to showcase the lethal effectiveness of the Silver Aura Battle Arts.