[thejeff]

Not to helpful for Lifelong protection, since it keeps making Imps.

Since it's a thug, Quicken Self, Attack, Attack, Attack, BoW, might be worth trying. It might cast if there are more enemies than friendlies around him.

But it's not just a deprecation. My best guess from the log is No enemies hurt :0, Some allies hurt: -value. Since the result is negative, the spell is forbidden. The 100,000 bonus for being scripted isn't added in. If it was, 100,000 - 49 would be far above any other spellscore.