"Then, we'll free her, too." Riou said, as they approached the doors.
OoC: Kinda reminds me of the Emperor of the Scarlet Moon Empire in Suikoden. The Witch Windy, bearer of a half of the Gate Rune, was using cursed Black Runes to control various members of his army (including a few that you recruit). You learn that he supposedly had one as well.
Except that his sword had the Sovereign Rune in it's hilt. Another True Rune. As a result, he was immune to magic. He followed Windy because he loved her. Not just because she reminded him of his dead wife, but also because he wanted to make her happy and to see her smile. He truly loved her, and that love blinded him to her evil deeds and he went through with them willingly. As he said, "This was my only sin. But it is a grave one, for which we must both be punished." With that he grabbed her, and jumped off the ledge of the balcony with her, to their deaths.