Quartz Von Beelzebub

Katakana: クォーツ・フォン・ベルゼーブル

Romaji: kwōtsu fon beruzēburu ("Beelzebub" taken from FFWiki

Original character from Nanaroku (Fortress76)'s Touhou fancomic Gensoukyou Great Sports Day ～ 200 yojana in a flash ～

First appearance at post #705944