Diablo 4 devs say you shouldn't expect Master Chief or any other Xbox characters to invade Sanctuary anytime soon

gamesradar.com:

Should you expect to see Master Chief or his iconic MJOLNIR armor appear in Diablo 4 anytime soon? The game's associate game director laughed off such a suggestion at BlizzCon 2023, with Brent Gibson telling me that "fans have speculated about all sorts of collaborations" following the acquisition of Blizzard Entertainment by Microsoft Gaming. 

While Gibson denied that the Xbox mascot will be invading Sanctuary anytime soon, he did leave the door open for future opportunities. "There's no plans right now that we could share," he says. Truth be told, it wouldn't be that out of pocket for elements of the biggest Xbox Game Studios titles to appear in Diablo 4, eventually. At the outset of Season of Blood, Blizzard released a batch of new premium cosmetics to the D4 store, one of which heavily inspired by World of Warcraft – one set includes a variety of mount skins and trophies once wielded by the infamous Lich King. 

Gibson says that the inclusion of items like these aren't mandated from above, but rather "all of these collaborations had to be individual conversations about how they would manifest." Game director Joe Shelly adds that he's always up for more opportunities to cross-pollinate across the portfolio, but only when it makes sense: "We are always interested in collaborating, when it's something that feels right."

"We're very careful in making sure that these things feel right," Gibson continues. "The team is passionate about keeping the dark tone, making sure that things stay appropriate – avoiding french fry swords." At this, Gibson and Shelly look at each other and laugh, so lord only knows what ill-fitting ideas they have fought off in the past. "So trying to keep things as true to the IP as possible is very