Alongside all the other upgrades and new goodies in Destiny's newest expansion, The Taken King, is the addition of three new legendary swords. Like the Blade of Crota, the new swords in Destiny: The Taken King function as a heavy weapon imbued with one of the three elements. What makes them particularly useful and worth the effort to get, aside from their stats, is that they all possess an upgrade that allows them to guard better versus two of the three other elements. For example, the Sol Edge deals out Solar damage, but it guards better against Arc and Void damage. The downside is that it does not dampen any Solar damage.
While the Sol Edge, Void Edge and Arc Edge are all fairly easy to get, players do need to know where to get all the materials for it. The whole farm can easily be done within an hour. Unfortunately, the quests to upgrade the swords to their exotic form will take much longer.