Secret of the Archmagi

Level 13

You can imbue two weapons with the rune of the eldritch knight. If you attempt to imbue a third weapon, the weapon infused first loses its rune and all benefits. In addition to the normal benefits, the runes grant the weapons one or more of the following weapon fusions (see page 191) of your choice: bane, corrosive, ethereal, flaming, frost, holy, merciful, shock, thundering, or unholy. You can grant no more than 10 total levels’ worth of fusions between the two weapons, and the bane fusion counts as a 10th-level fusion for this purpose.