On December 10th, 2013, YouTuber universalbean uploaded a video titled “Deus Vult!,” containing a slideshow of various paintings depicting the Crusades (shown below, left). On October 14th, 2015, YouTuber Metaphysical Gnome uploaded a video titled “Ave Maria! Deus Vult,” featuring footage of Christian soldiers in the Free Syrian Army (shown below, right).
On October 21st, Urban Dictionary[1] user speed_kill submitted an entry for “Deus vult,” translating it as Latin for “God wills it.” On March 2nd, 2016, FunnyJunk[7] user thedankmemer submitted a gallery titled “Deus Vult! Meme Collection” (shown below).
On May 6th, /r/The_Donald[6] moderator D4rkd3str0yer submitted a post titled “Meme Magic Friday: Deus Vult Edition” to the subreddit, inviting viewers to “bring down the holy wrath of meme fire” upon Donald Trump’s political opponents. On July 10th, Imgur[4] user TheBigGay submitted a gallery of image macros referencing the Crusades and “Deus vult,” which reached the front page of the /r/dankchristianmemes[5] subreddit two months later (shown below).

On August 22nd, YouTuber Starbot Dubs uploaded an animated web comic in which a crusader repeats the phrase “Deus vult” (shown below). On October 3rd, Redditor MarlRhane submitted a question about “deus vult” references to the /r/OutOfTheLoop[3] subreddit.

Why is everybody saying "Deus Vult" and everybody is making references to the Crusades. from OutOfTheLoop

You should look at the bottom of the comments at /u/ohgodhelpplease’s response. Although the top comments have some truth to them, the widespread usage of this meme is not really sparked by the game Crusader King’s, but more so by the migrant crisis in Europe, and groups like the “alt-right” coming to light recently.
There has been a widespread shift in a lot of people’s views about Muslim immigration, and many people voice the sentiment that the Muslim migrant crisis mirrors a “Muslimic take over” of Western civilization, or Europe as a whole.
This of course has caused many people to reference Muslim Jihad’s and Christianity’s response to Jihad by calling for Crusades. The phrase “Deus Vault” has been thrown around on a lot of right-wing and conservative websites and platforms as a sort of calling to either drive the Muslim’s out of Europe. Or to spark some sort of war against Islam again.

Edit: Before the flow of downvotes come, I don’t voice this opinion. But I’m subscribed to a bunch of right-wing platforms and Facebook pages. Whenever an article surfaces about a Muslim Migrant crime, or about the Muslim migrant crisis in general, a flow of “Deus Vault!” comments are spammed in the comment section. Not to mention a lot of people are photoshopping Trump’s head and a bunch of his followers onto Crusade pictures. If you don’t think that the widespread usage of “Deus Vault” has nothing to do with the anti-Islam sentiment or xenophobia, you don’t know what’s going on.

No, it’s definitely from CK2.
[–]Feint-Smile 21 points 1 year ago
I know it does have its roots in CK2 but a lot of right wingers are using it to express anti-Islamic sentiment in response to the Migrant crisis in Europe. Which I think is why it’s been so pervasive recently.

As you say– Same reason you suddenly hear cuck everywhere. They didn’t invent it, but they started using it a lot. Same with Pepe. They didn’t invent it, they just also use it for their own thing. Same thing with Deus Vult. They didn’t invent it, but you see them pushing it as their thing. Doesn’t mean anyone who says it is a right-wing supremecist, it’s just context on the issue.

A rallying cry adopted by For Honor players may sound familiar to those well-versed in the conservative political landscape. “Deus vult,” a phrase that’s become popular with the multiplayer game’s community, may have origins in 11th-century Europe, but it’s more recently been associated with the alt-right movement.

“Deus vult” is Latin for “God wills it,” which became a stirring declaration for the Crusaders. It concluded a speech made by Pope Urban II, calling defenders of Christianity to action in the fight to win back their Holy Land from its Muslim occupants. It became symbolic not just of pride in the Christian state, but in Western culture as a whole.

The religious, historical nature of the phrase is obvious and inextricable, and that’s what accounts for its use by the community of games like For Honor. The action fighting game is set in medieval times, with players choosing between knights, samurai and vikings. In keeping with the time period, players who choose the knight class can often be found cheering “Deus vult!”

The phrase is a major meme in the For Honor community, and it appears to be recycled from older medieval times-based games. That includes Crusader Kings, which had an expansion called Deus Vult; the phrase also appeared in its sequel. It’s used by recent beta testers in a plethora of threads on the subreddit and official For Honor forum. There are jokes about the meme and how common it is, but more often than not, players just post it as a rallying cry — much like how it was originally intended.