Tokyo MX's
summary matches up with Newtype's.
Episode 12:
Eternal Engagement (Kanji are for "never ending contract")
Yuuta is uneasy over Rikka's disappearance. While he is worrying, he is told why the Wicked Eye was born from the second user of its power. Knowing the truth behind her power, Yuuta heads out into the town to search for Rikka. The story of the Dark Flame Master and the user of the Wicked Eye is concluded here.
Script: Junki Hanada Director/Storyboards: Taichi Ishidate Animation Director: Chiyoko Ueno
Since it's the last episode, no need for spoilers in here about it.