Blizzard has announced two new characters for Heroes of the Storm, both of which come from its Diablo universe. Xul the Necromancer is the first of the Diablo II-exclusive classes to make an appearance in Heroes of the Storm, sporting his trademark ability to summon skeletons. Diablo 3's Wizard Li-Ming joins the fray alongside him, armed with an arsenal of high-damage spells.

The Necromancer's skillset allows for him to become a great assassin or split pusher, and the Wizard debuts as one of the game's highest skill-cap characters to date. To find out more about these two new additions to the roster in Heroes of the Storm, I spoke to director Dustin Browder about why these characters were chosen, raising the skill bar of players in Heroes of the Storm, and more.

GameSpot: Why two classes from the Diablo franchise? Was it intentional for the timing to tie in with the start of the new season in Diablo III?

Dustin: Nope, but that would have been a good idea. I like your thinking there!

These characters have been moved around several times, so the fact that they're together is kind of an accident. Necromancer has been a character that's been asked about for quite some time. Since 2013 people have been asking about Necromancer, and now we've finally got a kit that we were happy with. The idea for Li-Ming the Wizard actually started as specifically as, "Is there an easy-to-understand, but very high skill cap hero that we can do? An assassin, someone who can really blow people on. Who would that go on?"

We were looking around and we had this idea for a hero that was going to reset their cooldowns after they participated in an assist or a kill. Then Wizard came up as an option.

So one was motivated specifically by players asking for the character, and one was we had an idea for some gameplay we wanted to do, and asking who could make that work for us.

Xul the Necromancer is the first Diablo II-exclusive player character you are adding to the game. Was it difficult to recreate this character from a much older game to make it look like he fit in with the aesthetic of Heroes of the Storm?

I don't think art was as big a concern. We did Lost Vikings before, who don't fit in at all. Even our older games like Warcraft 3, if you go back and look, the art doesn't really directly translate from then to today. I think art is less of a concern, we're really going for something that reminds you of that character. What made Necromancer especially challenging for us was more on the creative side. Because most people remember the Necromancer as a billion skeletons. There's only so many skeletons our game can handle before it becomes very noisy, difficult to read, and he becomes invulnerable to all kinds of skillshots because of all the skeletons in the way. So he was more challenging to get something that was close to the Necromancer fantasy, to make it playable within the context of our game.

Did you work closely with the Diablo team to do that?

Some. A lot of the teams give us a lot of latitude when it comes to these heroes. They know that we're going to be using these characters, they know that we're going to treat them with as much love as respect as we can while shoving them violently into our game. They've been very supportive of the work that we've done. We give them a heads-up when we're doing stuff, but they're generally very supportive of our efforts.

How are the names for these normally nameless heroes chosen?

Sometimes the team can find someone obscure in some of the fiction that's been written or in a comic book somewhere. Sometimes even those become too specific and they simply use the types of names this character has had in the past to inspire a new name.

Do you look at any statistics from how players use these classes in Diablo III when introducing them to Heroes of the Storm?

Not generally. Generally it's challenging enough to make the core fantasy of the hero even function within the game than to worry about which build is optimal this month in Diablo III for example. We all have impressions from how we've played our Wizards in Diablo III, and that certainly influences the direction the hero goes. We've had popular builds made us consider how we make this character. Often though, just making the hero work within the context of the genre is pretty challenging and if we can hit that, we're going to call it a win.

There are times that we go away from that though. For example, I would argue that for Witch Doctor, Zombie Dogs is one of the most powerful iconic abilities for that character in Diablo III. But when we made that character we didn't think we could handle the span, we didn't feel like we wanted another pet class in the game at the time, our pet controls weren't that great when we put that in the game in the first place, so we went away from that. We feel like our Witch Doctor in Heroes of the Storm certainly feels like a Witch Doctor in Diablo, but the specific abilities definitely don't always translate back and forth.

Though to be fair, I think the Diablo team liked our circular zombie wall so much that they actually made a circular zombie wall in Diablo, which was nice to see our ideas inspire them. But generally, we try to get the feel for the character as best we can, but the specific powers we may not always be able to hit. But when we can, we're happy to.

Will these characters have quips that point to relationships with other characters outside of the Diablo franchise?

I know we often do the best we can in that area. Honestly, I'm not sure which ones the writing staff did for this.

With characters like the Necromancer, there's a huge pool of skills in Diablo II to choose from. How many iterations did you have to go through to tweak this character to be suitable for HOTS?

Wizard was fairly quick, as far as things go. Once we tested Magic Missile, we really liked that. Arcane Orb really worked the way we wanted it to. Disintegrate went in early and stayed there for quite some time. Necromancer went through quite a battle. Necromancer was back and forth many, many times. We had versions of the Necromancer that was all about skeletons. We had a sufficiently frustrated Necromancer who was named "I have no skeletons at all! Where my skeletons be at?!" at one point. So Necromancer had a lot more iteration time to get there.

I think that was also difficult because so many people had different ideas of what [the hero] should be. People remember different skills. Corpse explosion was something a lot of people remembered. It really depends on how you played it, and people became very passionate about which version of the Necromancer should ultimately go into the game. That was months and months. And I don't mean months to build, all characters take months to build. But I think there were… if we're supposed to be in a concept phase for a hero for six to eight weeks, he was easily twelve or more.

With the addition of a hero like Li-Ming, is it part of Blizzard's intention to push the skill level of players up higher?

The short answer is yes. The longer answer is that we're always making different heroes of different skill requirements. We've got Raynor, we've got Li Li, we've got a bunch of characters that are very easy to get into the game with. We'll probably add more of these down the road as well. Right now we're getting a fair amount of feedback from our players that they want to be challenged a little bit more. I want those opportunities as a player as well. I think you can see us look to put in some more challenging characters for a little bit. We may sometimes revert, and go back to some character that feels like hey, the mechanics for this character would really feel nice if it was easy to play, and we'll do that. But I think if you're asking is there a general trend in the coming months to make the characters more challenging to play, absolutely.

We're still not going to violate our values around what I sort of call the long tooltips, where it's like a novel to figure out what this character does. We still want the characters to be easy to understand. But the difficulty of execution is something I think you're definitely going to look towards adding some more layers to the game through those types of choices. We're also going to be looking at that with the talent system as well. We feel like we have plenty of easy-to-use heroes in the game but as we go through and redo some of these characters we may be adding some talents to the game that are like "hey, do you want to be challenged? It's a little bit harder, but there's a little more power here if you can pull it off."

We've got some of those in the game right now. I would argue that Azmodan's talent, where you can get stacks of damage on your Q based on killing minions has some teamwork associated with it and it also has a little bit of skill associated.

It's interesting you say that because part of what makes HOTS so successful is that it makes this genre of games accessible to players who don't normally play these types of games.

I don't think it's like we're not going to do that anymore, it's not like we're cutting Li Li or taking Raynor away. Those characters will always be there. When we're looking at re-doing ultimate talents for a hero I think you'll see us be cognizant of that when we're looking at those characters. We just want more depth to our hero roster. We've had characters for years that are harder to play and easier to play, we're just adding a little bit to one side than the other for now. But we're always looking to have a wide range of choices for our players coming so no matter what type of player you are, whether you want to sit down and relax or you really want to be challenged, that you have choices along those lines.