Grima initially known as The Creation is the main antagonist in Fire Emblem Awakening, and a secret boss in Fire Emblem Echoes: Shadows of Valentia. Grima tends to go by the title of the Fell Dragon and is feared by most of the world. He was created long ago by a legendary alchemist known as Forenus using the blood of a Manakete with a Divine Dragon form.
Grima originally had no name, and was just referred to as the Creation. Created by a mad alchemist named Forneus, he had gathered many materials, including the blood of a Divine Dragon, something that Forneus had taken a great risk to achieve, to create the perfect lifeform. With it, Forneus mixed the blood with human fluids, certain herbs and nectar, and sealed the concoction inside a vial for 40 days. This mixture resulted in the birth of the Creation.
At first the Creation was tiny, merely the size of a thumbnail, and resembled a human fetus. Keeping the Creation under a temperature of a horse's womb, each day, Forneus gave the Creation his blood. On the 80th day, the Creation began to undergo a transformation. It began to resemble less like a human, sprouting eyes, extending it's neck, and even growing a tail. Slowly, it began to take the appearance of an unusual dragon, not like that of a Divine Dragon that it was created from.
The Creation had six eyes that stared at Forneus through the vial, seeming to smile, indicating that it seemed to have developed a consciousness and was possibly smiling at Forneus. Eventually the Creation grew to the size of a puppy, but it was said to have a terrifying power, and seemed to have moments of rampage that Forneus attempted to control before the Creation reached full maturity.
The Creation's voice began to connect with Forneus, where both were able to see inside one another, and Forneus began to sense the dark and violent thoughts within the Creation, enough to make him heart tremble, while the Creation stared at Forneus trembling and smiled at him re-assuredly.
Eventually it reached a point that Forneus realized that his creation was too powerful to ever be controlled, and sought to destroy it. It is unclear exactly what happened afterwards, but it is presumed that the Creation killed Forneus in retaliation for his treachery.
Alm and his army goes inside Thabes Labyrinth in Act VI of Echoes: Shadows of Valentia, they eventually reach the end of the maze to encounter the Creation itself. After a fierce battle, the Creation is defeated, but despite that, it is mentioned that the malevolent presence that filled the place with a sense of dread never faded, implying that the Creation's spirit lived on.
Around a thousands years afterwards, the Creation returned, under a new name, calling itself the Fell Dragon, Grima. Grima presumably made a pact with a human, and tried to destroy the continent of Ylisse, but both were defeated by the First Exalt of Ylisse and Naga, with Grima put into a long slumber. A cult that fanatically worshipped Grima as the god of annihilation, the Grimleal, formed a country, Plegia, in order to revive their fallen master. For centuries, the Grimleal tried to create a suitable vessel for Grima to take, someone who held the Heart of Grima.
Eventually Validar, a failed vessel for Grima, produced a child with pure enough blood to be a suitable vessel, Robin. However, Validar's wife feared for their child's future and took them away to an unknown location, angering Validar and delaying their process of bringing Grima back.
In the alternate future, Grima managed to possess Robin and kills Chrom at The Dragon's Table, bringing destruction to the world. To prevent Lucina from interfering with his resurrection in the past, Grima followed her through time, but ended up losing a large amount of his power in the process. He managed to find his past self's body and attempted to fuse with Robin to give himself his blood and restore his power, but the massive amount of memories and the weak Heart of Grima Robin had at the time gave the past Robin amnesia and caused Grima to lose even more of his power. After Validar's death in Chapter 6, Grima approaches Validar and revives him for his grand purpose.
Two years after Gangrel's defeat, Validar introduces his hierophant, a hooded figure who looks exactly like Robin. However, before Chrom and Robin can ask further, Validar reminds them to make haste to prevent Valm's invasion. After stopping Walhart and the Valm empire, Chrom returns to Plegia to receive the last Gemstone, only for Validar to betray them by stealing the Fire Emblem. With the Emblem in hand, Validar rushes to The Dragon's Table to perform the Awakening and resurrect Grima. Though Validar is killed before Grima's Awakening can be completed, the mysterious doppelgänger met in Plegia before the Valm invasion warps onto the Table. The doppelgänger reveals that their exact same appearance with Robin is because the body they use, is in fact, Robin, the alternate future version of the Robin from the same time as Lucina and the other children. Unlike the present Robin, the future Robin was successfully possessed by Grima, killed Chrom, and led the future to its ruinous state. The Grima-possesed Robin tries to persuade the present Avatar into accepting the Fell Dragon's influence. Taking the present Robin's question about not yet being the same as their refusal, undeterred, the Grima-possesed Future Robin decides to finish the Awakening himself by sacrificing the Grimleal, and powers up the Grima of the present. Both Grimas leave the Dragon's Table to go to Origin Peak to regain the remaining power they need to destroy the world.
After Chrom completes the Awakening, he learns that if he deals the final blow with the Exalted Falchion, Grima will only be sealed for another 1,000 years. However, if Grima dies by his own power, only then can he be killed permanently. At Origin Peak, Robin realizes that their link to Grima means that if they kill Grima, Grima will be "killed by his own hand." However, Naga warns them that if their bonds in this world are not strong enough, they will die in the process. After defeating Aversa, who led a band of Grimleal to avenge Validar's death, Naga teleports them onto present Grima's weakspot, Future Grima on his nape, although they prepared in advance and protects themselves along with the remaining Grimleal. After both Grimas are weakened by the Shepherds, the player can decide Grima's fate. If Chrom is allowed to land the final blow, he will send Grima into a state of slumber for one millennia. If instead Robin lands the final blow, they will charge up a ball of energy, and Grima will ask them what they are doing. Robin responds that they are glad the two share something together and how the evils he would visit on this world would be unforgivable and believe they should meet their end together. Future Grima yells in despair as Robin launches the ball of energy on him, killing both Grimas. As the Grimas die, Robin also begins to fade away as the two are linked together. After an undisclosed amount of time, Chrom and Lissa find Robin on a hill, this time the Mark of Grima is missing from their hand — a sign that Grima is gone for good and the world can now enjoy peace.
- Grima's Japanese name may be named after Gimlé, a place in Norse mythology where the survivors of the Ragnarök are supposed to live.
- Grima's creation method by Forneus, as well as the form Grima took as a human fetus, seems to be very similar to the method to create homunculus.