Not exactly like Diablo, but an absolutely awesome isometric game with guns is Crusader: No Remorse.
It's 20 years old, but IMO it still holds up. I'm sure you could pick it (and it's sequel No Regret) up for dirt cheap on GoG probably.
Fuck yeah! I sunk so many hours into the Crusader games on both PS1 and Saturn.
The first one was ported to PS1 and Saturn in 97. The graphics weren't as good but it still kicked ass.Huh, didn't even know they were available on consoles. I played them on PC and just assumed that's all they were ever on.
Yeah it's totally weird. I am going to give it a chance.Just a little hint, and you may be different than me...
But fuuuuuuck the steam controller. Bought it, had it a week, returned it. It is NOT just like using a regular controller to play with.
Have not heard that game brought up in a very long time. It was an awesome game but it never got off the ground really. So much potential.Hellgate london describes what you are looking for