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?!
They let the wielder pass their 
mana and stamina to allies,
يمكّنان الحامل من نقل المانا
،خاصّته ولياقته لحلفائه
Damit kann ich meine Kraft und
Ausdauer an Kameraden senden
Puedo compartir mi magia
y fuerza con mis compañeros
Puedo compartir mi magia
y fuerza con mis compañeros
Avec elles, je partage ma force
ou ma magie aux alliés
Permettono a chi le brandisce di passare
il proprio mana e la propria resistenza agli alleati,
Elas permitem que o portador passe
seu mana e resistência para os aliados,
Они позволяют владельцу 
передавать ману и выносливость