Things Left Unseiðr
Things Left Unseiðr is a story written by Kirisaki Nizuki. It ran in Issue 39 at http://s2b2.livejournal.com/227887.html, and is mirrored at http://www.shousetsubangbang.com/mirror/things-left-unseidr/.
From isis.dreamwidth.org: "Intriguing Old Norse setting for this story about a man who practices a variety of sex-magic usually only performed by women."
From fail-fandomanon.dreamwidth.org: "Vikings perform sex magic to win a battle. Includes lying back and thinking of Viking victory."