Diablo is, without question, one of the most successful and influential video game series of all time. Blizzard North had a modest outlook for the release of the first game in 1997. Co-designer Max Schaefer has been quoted as saying they would have initially considered it a success if it sold 100,000 copies. Instead, it ultimately sold over 2.5 million. Diablo II sold 4 million copies in its first year alone. Diablo III sold 3.5 million copies in its first day. In addition to boasting such impressive sales figures, the main games of the series have been generally very well-reviewed. Diablo and Diablo II have both been on many, many lists of "best games ever" from reputable reviewers. In general, it's hard to overstate the impact the series has had, to the point where many other action RPGs released since 1997 have been dismissed as mere "Diablo clones".
The setting for the games, the world of Sanctuary, seems ready-made for comic book adaptations. Humans, it turns out, are the descendants of angels and demons who fled the Eternal War between Heaven and Hell, opting instead to live in a backwater material world away from the carnage. Until, of course, Sanctuary is discovered, and becomes a new battleground. So, of course, the comic adaptations made the same sort of genre-defining impact in this industry that the original video games made in theirs, right?
Right?
Not... so much, actually. The Diablo comics that have been released are generally well-presented. They're fairly well-written. They're illustrated by skilled artists. But they didn't attract much attention at all. They didn't sell. Especially on the scale of other modern comics published at the same time, every single Diablo comic adaptation is surprisingly scarce for a title paired with such a behemoth of a property. In fact, DC's 2012 Diablo limited series sold so poorly that that last two books dropped off the bottom of Comichron's index of orders placed through Diamond Comic Distributors. And that's still a better fate than befell the 2018 series from Titan Comics. Although at least the first issue was apparently completed, and several variant covers prepared and solicited for preorders, Blizzard ultimately decided to cancel the series entirely (the general belief is that some element of the story conflicted with the plotline then-in-development Diablo IV). No copies have ever emerged, and I rather suspect that it never saw print at all.