By Three They Come - Side Quest Easter Eggs

Diablo IV Announce Cinematic | By Three They Come
On November 1st, 2019, Blizzard released their Announce Cinematic for Diablo IV, titled ‘By Three They Come.’ This cinematic created so much hype for the game and revealed the main antagonist of the story, Lilith. The Cinematic shows the story of four adventurers trying to get into a tomb that they believe holds ancient treasures. Little did they know, they were stumbling upon a ritual site where Elias would use their blood to summon Lilith, The Daughter of Hatred.
By Three They Come - Quest Line
In Diablo IV, there is a quest line in Hawezar that ends with you entering the Halls of Dark Portent, where the summoning of Lilith takes place.

When crossing the bridge, the game view zooms quite far out. This helps capture the scene and allows you to instantly draw the connection to the trailer if you have seen it before.

The quest area is scaled identically to the cinematic. After you cross the bridge, you will stumble upon the seal, where Symon finds out that blood is the key.

In order for your character to get through, you must break down the door.

Like in the cinematic, you are faced with a horde of ghouls upon entering combat by attacking the door.

After a few waves, the seal is broken, and you are able to enter the ritual site where Lilith was resurrected.

At the foot of each pillar lies the bodies of the adventures that Elias used to summon Lilith, including Symon.

The pillar to the left has the corpse of Gelwa, the female Barbarian that we see in the trailer.

On the right, we find Fionn’s corpse. Fionn was the male Rogue who had betrayed the ‘One-Eyed Swordsman,’ holding Symon back and leaving him behind.

Lastly, at the end lies the body of Symon. In this questline, you learn a lot about Symon and realize how cruel and undeserving his death was. Your character even comments on how Symon deserved better.
As you can see, there are blood petals surrounding the center of the ritual and the three pillars, which are raining from the portal Lilith came through.

Quest Reward - One-Eyed Swordsman's Blade
Upon turning in the quest, you receive the Rare Sword called the ‘One-Eyed Swordsman’s Blade.’ In a few scenes of the cinematic, you can see him wielding this sword.

The description of the sword reads: "By the blood of the willing, we call her home." While Symon is lifted up to the pillar, these are his last words, completing the ritual.
