Diablo 4's new expansion 'Vessel of Hatred' will introduce mercenaries to help you out on your quest, and at Gamescom Opening Night Live, Blizzard shared a new trailer featuring these helpers.
Here's a bit more about these recruits via Blizzard's official website:
"Discover and recruit new Mercenaries to join you on your quest. These powerful allies fight alongside you, grow in power as they progress, and help you in combat with unique abilities."
Vessel of Hatred will launch on October 8th, 2024, with the base game now available on Xbox Game Pass. If you pre-purchase the expansion, you can also unlock multiple goodies, as seen in the trailer above.