Diablo II was the game that got me into gaming, and Diablo III was pretty good too. In Diablo II all the names are different cultural names for the devil. Yes, Diablo IIi uses actual demon names, but it’s a fantasy game, in a fantasy world. Blizzard is notoriously pretty lazy with their naming, it’s not like playing the game is going to summon an actual demon. Those games very much have a good versus evil theme, and the players are clearly on the good side.
The morality of any video game, like any form of media depends greatly on how they affect the individual. I can play games like Diablo and not want to start summoning demons so I can shoot ice lasers at them. Just like I can play games like Skyrim and not want to start shouting people to death while leading an assasin cult. But there’s some people that are affected more by that stuff. If you feel like it’s having a negative impact on you don’t play it, if you feel like it’s neutral than go for it. I have not played HotS, but yeah, can’t see any reason why it would be bad. I mean it’s Blizzard, their mildly suggestive themes consist of the occasional innuendo that not even a 12 year old would even giggle at.