Tyrfing

"Holy Sword" Tyrfing was the sword of the Crusader of Light in Fire Emblem 4. In the game only characters with major Badlo blood could wield it, meaning the only playable characters that could wield it were Sigurd and Celice. The Tyrfing had a 30 might and gave a +10 Skill, +10 Speed, and +20 Magic Defense to its wieldier. Because of the huge Magic Defence the Tryfing provided, as well as its 30 might, it made defeating enemy mages much easier even making it possible to defeat Julius without the use the Narga spell. Due to that Celice (and to a lesser degree Sigurd) is often regarded as a mage killer when equiped with the Tyrfing.