"Unknown One at the Bottom of the Deep" is episode 158 of the Berserk manga.
Luca thinks that the circumstances she finds herself in are utterly surreal: she is atop a gigantic armored horse, a man in skeleton-themed armor who she thinks is Death has his weapons drawn and is bidding a small mysterious being to come out and fight. She feels an unearthly air around herself.
The Skull Knight stands several feet from the being, ready to fight. It tells him that living humans aren't welcome among the burial grounds. Regardless, the Skull Knight steps forward, so the being extends its tentacles and lashes out at him. With barely any effort, the Skull Knight swings his sword, cutting the ends of each tentacle. Suddenly afraid, the being leaps over Skull Knight entirely, but is still struck on its underside by his sword. The being does not lose its composure however, and aims its landing directly at Luca. It uses its front bug-like legs to pick her up and leaps away. The Skull Knight doesn't give chase, knowing that it can't get too far with its new. He has, however, taken an interest in the specific form that the creature has.
Luca wakes up in a small cave that is filled with lit candles. She is disturbed by the grim centerpiece which bathes in the light created by the candles: a large cross-shaped figure reminiscent of the hawk symbol used by the Holy See, except this one is much bigger and is made of human skin and bones. Luca's internal questions about the statue's nature are answered by the mysterious being, which sits at its foot. The statue is made of the skin and bones of priests.
When Luca asks who the mysterious being is, it replies with a story: the being has no name. Back when it was human, it lived in the shadow of the Tower of Conviction, away from the other people who lived in Albion. As a human, the being was deformed and ugly, and thus couldn't go out during the day, as the population of Albion would be frightened and throw stones at it. It dug a hole at the foot of the hill where Albion is located, sitting inside it all day, completely still. Every day, it would deepen the hole to further hide from humanity. As it rummaged around at night, it came across a small egg-shaped object. One day, as it sat in its hole, the first of many corpses was thrown down its hole by the humans above; they intended to make it a burial hole to dispose of their dead. As the corpses came falling in, the being was buried with them. As it started to lose consciousness, five angels appeared before it. They offered an exchange: they would grant one wish to the being in exchange for something that was dear to it.
In exchange for the current, grim world, the being wished to be the one to birth the "perfect world". As a result, it has taken on the form of an oversized Beherit on four spindly legs.
Characters in Order of Appearance