The Viper class is one of the many classes you can unlock in Final Fantasy XIV. It was added to the available list for the Dawntrail expansion, and if you have access to that DLC, you'll be able to train up your Warrior of Light.
An Idiot's Guide to VIPER | FFXIV Dawntrail
How you approach the Viper class is similar to the other Final Fantasy XIV classes. You’ll have an initial quest to complete, but thankfully you won’t start at level one. Instead, you’ll start 10 levels below the required level you need to be to start the Dawntrail expansion, meaning you’ll have some more leveling to do before you can begin your new adventure.
The Viper class becomes available after you unlock the Dawntrail expansion. If you do not have this expansion on your Final Fantasy XIV account, the quest will not appear, making it impossible to obtain. After confirming your access to this expansion, the next step is to head to Ul'dah – Steps of Nald and visit the Worried Weaver at the coordinates (X:8.1, Y:9.3).
As you might expect, this quest for this class is relatively straightforward. You shouldn’t worry too much about the intensity, and once you’ve completed it, the Viper class is now yours to begin mastering in Final Fantasy XIV. It’s a melee, DPS class, meaning you can expect to take on your enemies in close-quarters combat, wielding powerful blades to cut them down.
