The Hellhound (also known as the Beast Of Darkness) is a creature which sometimes appears to Guts, taunting him, questioning the morality of his quest for revenge, and urging him to commit ever-greater atrocities, most notably attempting to convince him to rape Casca. While it at first appears to be a demon or evil spirit of some kind, it also appears to Guts inside Godo&#039;s cave which evil spirits cannot enter. This would seem to imply that it is either a hallucination or otherwise a part of Guts&#039; mind.    The Hellhound might be the embodiment of Guts&#039; own rage and hatred at the God Hand, the Apostles and especially Griffith after the Eclipse. Among other things, it wants Guts to kill Casca so that he can get back to seeking revenge.     The fact that in the past (volume 5, chapter 3: Wind of Swords) Casca shouted in anger to Guts that he is just a &quot;mad dog&quot; it is probably the reason why his inner beast is represented as the Hellhound.     When Guts uses the Berserker armor, the helmet appears very similar to the Hellhound&#039;s head. The Hellhound appears to be strengthened by repeated use of the armor, but is held in check by Guts&#039; affection and loyalty for his companions. These two forces are constantly at odds: in his latest appearance, the Hellhound seemed larger and stronger than ever, but was bound by thick chains. However the Hellhound has vowed should the time come when Guts was too weak to subdue him, the Hellhound would break free and take over Guts and kill all those Guts held dear. 

His name is Guts, the Black Swordsman, a feared warrior spoken of only in whispers. Bearer of a gigantic sword, an iron hand, and the scars of countless battles and tortures, his flesh is also indelibly marked with The Brand, an unholy symbol that draws the forces of darkness to him and dooms him as their sacrifice. But Guts won't take his fate lying down; he'll cut a crimson swath of carnage through the ranks of the damned—and anyone else foolish enough to oppose him! Accompanied by Puck the Elf, more an annoyance than a companion, Guts relentlessly follows a dark, bloodstained path that leads only to death...or vengeance. 
 
(Source: Dark Horse) 
 
Notes: 
- Volumes 1-5 contain the 16 prequel chapters 0A - 0P. 
- <a href="https://anilist.co/manga/95821/">Chapter 83</a> was omitted from Volume 13 due to the author’s request. 
- Volume 14 includes “<a href="https://anilist.co/manga/36408/">Berserk: The Prototype</a>”. 
- Due to the author's passing, starting from Chapter 365, the manga is illustrated by Studio Gaga (Miura's assistants) and supervised by Kouji Mori (a close friend of Miura's).

Second season of Berserk. 
Demons have now become commonplace around the kingdom of Midland, which has fallen into chaos. The swordsman Guts still cannot stay in one place for long due to his demonic brand. He could always manage to protect himself when he was alone, but now he has the added challenge of protecting former Commander Casca, a shell of her former self who neither remembers nor trusts him. They never have a moment's rest with the constant threat of demons, and they need a place where Casca will be safe till they find a way to heal her. Their elf ally, Puck, tells of the mystical land of Elfhelm, which is supposed to be a safe haven from the demons that ravage the lands. Tired and with only a vague hope, they struggle on to find a place to live—and they still need to find those responsible for the madness they are forced to endure.

Yami no Kemono