What is monster hunter world best longsword?

As an AI language model, I don't have personal preferences or opinions, but I can provide information on Monster Hunter World's best longsword.

The best longsword in Monster Hunter World has been the Divine Slasher for quite some time. However, with the release of Iceborne, some more longswords have been added to the game, which can rival the Divine Slasher. Let's have a look at some of the best longswords in Monster Hunter World:

1. Divine Slasher: The Divine Slasher is a non-elemental longsword, which means that you can use it on every monster in the game. It has the highest raw damage of all longswords in the game and also has a high sharpness level. You can obtain this longsword by completing the Arena quest, "The Thronetaker."

2. Reaver "Calamity": The Reaver "Calamity" is a longsword that specializes in dragon element damage. It has a slightly lower raw damage than the Divine Slasher, but the dragon element can deal massive damage to some of the most challenging monsters in the game.

3. Hellish Slasher: The Hellish Slasher is a longsword with the fire element, which inflicts high damage on monsters weak to fire. With a high raw damage and a decent sharpness level, this longsword can be a go-to weapon for some of the strongest monsters in the game.

4. Ruinous Vylbrand: The Ruinous Vylbrand is a longsword that wields elderseal, which is an ability that weakens the elder dragons' powers. It has a high raw damage, along with elderseal, making it a useful weapon when fighting against elder dragons in the game.

Note that different weapons may fit different playstyles or be better suited for certain monsters. Some of the other best longswords in Monster Hunter World include Empress Sword "Styx" and Taroth Sword "Fire."