Grendel

is a monster appearing in the legend of Beowulf, appearing in Fate/Grand Order.

Background
Beowulf fought and killed Grendel and in life.

Appearance
Grendel changes appearance in accordance to the situation.

Personality
Beowulf describes Grendel as an evil creature that plays with human lives, "the kind of evil that reveled in the meaningless slaughter of people trapped in their dwellings." He is not something that fights over territory or his own survival, but Grendel was simply just an evil being with both reason and intellect. Initially, he is unable to speak, but eventually gains the ability based upon speech in the memories of his opponents. Upon speaking, he exclaims he must commit acts of evil, as that is what makes him Grendel.

Role
Grendel appears in the Rome Singularity after Beowulf is summoned by Ritsuka Fujimaru, summoned along with Beowulf as an anomaly in the summoning process. This hinders Beowulf's usage of the Grendel Buster Noble Phantasm. Grendel is closely tied to Beowulf, having been the only monster in his life with "such fierce hatred and glory." Beowulf decides that he must kill Grendel due to it being a thing that should not be allowed to exist in the world.

Grendel devours a castle's worth of humans after his summoning, the aftermath found soon after by Beowulf, Ritsuka, and Mash. Grendel attacks them in the form of a Chimera, but they drive him off. Detecting him with Hrunting, the group chases after Grendel, soon finding him in the form of a human soldier begging for help. Beowulf sees through the disguise with his sword, and they drive him off again. Beowulf warns Mash of his ability to appear as someone close to them, and they encounter him as Jeanne, Nero, and Drake. Grendel says he does not know why he was summoned, but that he will do what he must to kill them in a cruel way om cold blood.

Upon defeating the three Servant bodies, Mash exclaims that even though they are fakes, the sensation of attacking them still disturbs her. Though it seems to be over, Beowulf warns them Grendel would not go down without a struggle. They find Grendel in a cave connected to the cellar of the castle, cornering him, and he makes a last attempt by turning into the dragon that killed Beowulf. They manage to defeat him, Beowulf telling him that Grendel is the one he wanted to meet the least. Grendel is confused that the dragon form proved ineffective, but Beowulf explains that he fears Grendel the most, and that the dragon was just what dealt the killing blow. He says the dragon did not frighten him, telling Grendel that he should have relied more on his own strength before fading away.

Abilities
Compared to the nameless dragon Beowulf faced, he feels Grendel is much more of a threat due to his intelligence. Compared to passive dragons that will not seek battle unless provoked, he considers Grendel as a "twisted monster who revels in evil." Upon being summoned, Grendel consumes human flesh and souls to gain more power and evil intent, slaughtering many to increase his power. Beowulf wants to kill him before Grendel obtains his perfected form.

Grendel is a "protean creature" able to change his form depending on the situation, reading peoples' minds to gain information and transform into those his victims know. He is hard to detect due to that, so Beowulf makes use of Hrunting to track him. He can replicate armor and clothes, in reality hardened skin, and replicate weapons, which in reality are extensions of his claws and hair. He can split into multiple beings at once to attack.