Death Ruler and Berserker

Death Ruler and Berserker (死の支配者と狂戦士) is a collaboration game event in Mass for the Dead with characters from Overlord and Berserk. It was released on May 1, 2020 to May 15, 2020. The event was re-released on October 20, 2021 to November 10, 2021.

Background
Upon realizing it, Guts and Schierke were in the dark. A world different from the World-a chaotic area. There is a path to the lower levels here and only the enemy.

Incident
Guts and Schierke find themselves in a strange new world. Several Chaos Beasts led by a Warrior Chaos Beast emerge from the shadows and attack. Guts manage to dispatch them but soon the two see a familiar figure, Zodd who declares his intention to devour Guts. The two warriors clash and after Guts defeats the demon, realizes that 'Zodd' was an illusion as he vanished on the spot after being defeated. Schierke wonders perhaps they are somewhere in the Abyss and perhaps what he fought was just a phantom from his memory.

The two continue on in their journey through the alien surroundings when another figure emerges, revealing it to be Griffith. Guts much wiser sees that she is not real like the 'Zodd'. The Griffith illusion prepares to fight seeing he is not fooled. He struggles with he and succumbs to his dark side and dons the Berserker Armor and defeats the illusion. His victory comes at a cost as he is struggling with his sanity.

Just as the two leave the area, new figures emerge from the mists: Momonga, Demiurge, Cocytus, and a troop of Skeleton Warriors. Momonga seemingly notices the pair pauses his party. Thinking that they are more enemies, Guts orders Schierke to run as he charges at strangers. Demiurge shifts into his Imp form and Cocytus takes the first blow from the mercenary. He counters with an attack of his own and the two engage in a sword fight. They are interrupted by the sudden appearance of the Skull Knight who comes to Gut's aid. Guts surprised by Skull Knight's appearance is ordered by the latter to concentrate on escaping the place first. Momonga thinking that they are threats pushes on the attack. Guts, Skull Knight, and Schierke however both manage to flee on Skull Knight's mount who passes Momonga. Rather than pursue them, Momonga orders his subjects to stay their hand and allow the strangers to flee. For the reason why, he senses that Skull Knight is not an opponent they want to fight.

Aftermath
In the Physical World, Skull Knight has brought his two allies safely back. The knight leaves without a word, leaving Guts confused about what actually happened. Schierke though says they should head back to their base to which he agrees. Walking back, Guts wonders about those monsters that he faced in the strange world.