Upon their first meeting, Issei disliked Elmenhilde due to her intentions to take Gasper for his ability and was angered when she discriminated Issei for claiming him to be nothing more than a mere servant with no qualifications, despite him being the Red Dragon Emperor. After the events that traumatized her in Volume 16 and reunited in Worldly Desires of Steel short story after he saved her from a stray devil and touched by his kindness, her selfish demeanor has lowered and they become friendlier, with Elmenhilde appearing to have developed feelings for him. She eventually became a member of his team for the Azazel Cup as his pawn. When Issei asked her about why she wishes to enter the tournament or wants to join his team, she remains silent while blushing. During the match against Dulio Gesualdo, upon tasting his blood, she finds it delicious, and it gives her remarkable strength.
Millarca is an acquaintance of Elmenhilde as both of them are from the Carmilla Faction. The two appear to be on good terms as Millarca jumps in joy and hugs her upon meeting. Elmenhilde was also aware that Millarca became a student at Kuoh Academy.