Originally a limited giveaway of 50 licenses on the 19th August last year. https://game.giveawayoftheday.com/warhammer-vermintide-2-winds-of-magic-2/
You do require the base game Warhammer Vermintide 2 to be able to add this to your Steam account.

Warhammers Vermintide 2 Winds of Magic

In Brief

A First Person Hack and Slash Atmospheric survival open world dark fantasy adventure game, with lots of violence and gore

Introduction:

The first expansion for Warhammer: Vermintide 2 brings a brand new enemy faction and new challenges to the game. As a meteor crashes down in the Reikland, Beastmen emerge from the depths of the Reikwald forest and rush to the epicenter to claim it as a Herdstone. It is up to the five heroes to stop them before a dreadful disaster strikes the Empire.

Features

New Enemy Faction: Beastmen
New Higher Difficulty
Raised Level Cap
New Progression System
5 New Weapons - One for each hero
New Adventure Level: Dark Omens
New Game Mode: Winds of Magic -

Intro & Features Reference accessed HERE. 19th August 2019

Installation:

Assuming you win a Steam key for Warhammer: Vermintide 2: Winds of change, once you've found it (should be sent to the email you used to enter the giveaway - it must be the email you first used to sign into the game giveaway site. If you’ve used a throwaway email there may be problems getting a key, because the key may be sent to that email. If you have any problems, use the contact form HERE. You must firstly have Warhammer Vermintide 2 installed and activated before you can add the Steam key for this expansion. Once activated it will be permanently tied to your Steam profile and you'll be able to install the game at anytime, anywhere on any computer, so long as you can validate who you are (usually via emails etc.). If you don't have a Steam account, you will first have to download and install the Steam client HERE

Then create a Steam profile/account. Once that has been completed and you've activated the base game, you can input the Steam code that you've received (after completing the form filling) via the game button along the top of the Steam client, (located between friends and Help). From the drop-down menu select 'Activate a product on Steam'. This opens a product activation window. Just follow the prompts to complete activation. Once the Steam code has been accepted, the game will be associated with your Steam account and can be installed any time you wish.

The Game:

Before you can install winds of Magic, you'll first need to have the base game Warhammer: Vermintide 2 installed. you can read my review of that game HERE . Although there is a new mode and other upgrades included with the new expansion, its still useful to familiarise yourself with the base game to put things into perspective.

The expansion, Winds of Magic, includes a new game mode plus you get to face a new enemy called the Beastmen; a hybrid human beast that not only have the intelligence of men, but the cunning of wild animals. and these add new challenges via Okri's challenges for example Locate all the runes left by a band of Beastmen (Dark tongue 1, Locate and enter the Beastmen's liar (Dark Tongue II) and recover the Beastmen's spoils (Dark tongue III), plus there are another 18 challenges included with the winds of Magic expansion for example there are five just for completing Dark Omens on the various difficulties i.e. Recruit, Veteran, Champion, Legend and Cataclysm called respectively Sorcerer's Test Subject, Sorcerer's Apprentice, Sorcerer's Understudy, Sorcerer and Liche. also included with the new expansion is a raised level cap from 25 to 35 (if you don't have the wind of Magic expansion, the base game has also benefited from some of the Wind of Magic upgrades as the level cap has been raised from 25 to 30. There are also new talents and a new progression system. There's also a new adventure level called Dark Omens where you fight the new enemy Beastmen in cooperative play with friends and strangers via the join-able online lobbies. You can set up your own server and make it public or private so as only to include friends. Unfortunately, unlike the two dlc's that were released last year i.e. Shadows Over Bögenhafen and Back to Ubersreik, where only one person playing in a cooperative game required the dlc for all the group to play; Winds of Magic requires all players to own the expansion, so if a friend doesn't they cannot join your server.

You five heroes also a get new weapons to play with i.e.

Sienna can swing her flames with a flaming flail.
Saltzpyre now has a billhook.
Kruber can use a heavy spear.
Kerillian has a shield and spear.
Bardin has a new set of throwing axes.

What Winds of Magic introduces to the game is 120 levels of what we call the Weave Mode, which can be accessed once you've completed the new Dark Omens map. The weave mode has a completely seperate progression system from the main game. To progress you collect essence from dead enemies, which can then be used to upgrade both your weapons and characters traits and perks via the cauldron found in your base keep. You can also upgrade the cauldron to increase the options for these customization.

The weave mode resets seasonally so that all players start afresh from level 0. Unfortunately you wont be able to play these until you have to complete the whole of the Warhammer: Vermintide 2 Campaign. Once you have, you'll then be able to access the Weaves. Theses are where section of the game map is combined with one of the winds of magic of which there are eight (see list below) to modify it in some way, for example if you have the wind of life melded to the map, it sprouts a bush with thorns from all the enemies you kill, which can cause significant damage to your enemies. The wind of heaven creates bolts of lightning that strike your enemies withing a perimeter around your heroes. Weaves have been balanced for online cooperative game play and not for single player game play.

Each weave map includes an objective that once completed by your team, will lead you to face a final challenge. You can read all about Warhammers Winds of Magic and their associated lore and effects via a fan site HERE. There are eight different winds of magic:

Wind of Light (Hysh)
Wind of the Heavens (Azyr)
Wind of Metal (Chamon)
Wind of Life (Ghyran)
Wind of Beasts (Ghur)
Wind of Fire (Aqshy)
Wind, the Wind of Shadow (Ulgu)
Wind of Death (Shyish)

Because I won't be able to complete the whole of the Warhammer Vermintide 2 campaign and the new Dark Omens map introduced in the new expansion, before the limited giveaway is over I've linked to a few more in depth reviews of the new expansion HERE, HERE, HERE, and Steam community comments HERE. you can also see several videos of game play for the new expansion HERE, HERE, HERE, HERE, HERE, HERE.

Final Word

I've suggested to some friends who i play online with regularly that we check out Warhammer Vermintide 2 together. They all purchased a copy while it was on sale last week . What I'm not sure about yet is whether or not only one person in a team requires the Wind of Magic expansion for all those playing cooperatively to experience the expansion. I've read that it is sometimes difficult to match up your p[articular level when completing a weave map. If you are playing regularly with a group of friends then this shouldn't be an issue as you will all level up at the same time so progression will be painless and smoothly done. I will add a note to this review to either confirm whether you can or not play with just one member having the expansion. The dlc's are only required for one coop player to own, so I'm hoping it will be the same for the expansion. :)