Additional voice cast members have been announced for the anime production "Yasei no Last Boss ga Arawareta!" (A Wild Last Boss Appeared!). At the same time, a third promotional video and a new key visual offer deeper insights into the story world.

The cast expands with several central characters:

- Hayami Shō takes on the role of Orm, the Demon King, who is considered the actual final boss in the game "X-Gate Online".
- Hino Satoshi plays Mars, the fire aspect of the Seven Luminaries, a subordinate of the Demon King.
- Matsuoka Yoshitsugu lends his voice to Jupiter, the wood aspect of the Seven Luminaries.
- Horie Shun embodies Minamijūji Sei, a newly summoned hero who opposes the Demon King and the Ruler of the Black Wings.

A newly released key visual shows thirteen characters and illustrates the power-political relations in the world of Midgard. At the center are the members of the Rule of the Twelve Luminaries, the followers of the protagonist Rufus. Three competing factions – the followers of the Ruler of the Black Wings, the group of the Seven Heroes, and the demon race – are depicted in dynamic opposition.

The third promotional video presents action scenes between these three conflicting groups and conveys an impression of the battle-oriented plot.

The story follows Rufus, a character who was banished by the Seven Heroes but is summoned as a hero against the demon race. This plot constellation forms the basis for a dark fantasy narrative with elements of summoning and rebirth.