Sure, there's already too many Warhammer 40,000 games flying around on Steam and mobiles right now. But you know what we don't have? Warhammer 40k games crossed with Diablo. And I could totally use more of those.
That's the basic hook for W40K: Inquisitor - Martyr, an action RPG being developed by Neocore Games, the same team behind Deathtrap and The Incredible Adventures of Van Helsing. It's billed as an open world sandbox game with a story mode and co-op for up to four players, although the gameplay seems a little more on the Helldivers side of things.
W40K Inquisitor - Martyr is scheduled for release next quarter, although the official FAQ says "a lot depends on the Founding". The "Founding" is basically a marketing push to encourage people to pre-order, so the game would presumably be delayed if the reception isn't that strong.
Nonetheless, an ARPG in the W40K world works for me. The first two Van Helsing games were decent too, so fingers crossed for this one.