Seiichi and Saria train under Artoria to become adventurers. During their training the three of them are teleported into a dungeon by a demon’s trap.

The dungeon they find themselves in the stronghold of the Black Dragon God, the strongest member of the Demon Lord’s Army. Artoria gets separated from Seiichi and Saria in the dungeon and the giant Black Dragon God appears before her. Then that overwhelming threat attacks! Can Seiichi and Saria save her in time?!
Anyone who runs into him 
has the worst luck of all.
من يلتقيه يكون صاحب
أسوأ حظٍّ قطّ
Wenn man ihn trifft, hat man echt
das größte Unglück auf der Welt.
Quien se tope con él,
es que tiene la peor suerte del mundo.
Si alguien se topa con él,
es que tiene la peor suerte del mundo.
Il faut être le pire des malchanceux
pour tomber sur lui.
Chiunque si imbatta in lui
è il più sventurato di tutti.
Se acabar dando de cara com ele, você
será o cara mais azarado do mundo.
Попадётесь ему на глаза — 
ройте себе могилу.