Thunder sticks collided as Jeff Kaplan took to the stage in front of thousands of people seated inside the Anaheim Convention Center Arena on Nov. 2, 2018.

"What is up, BlizzCon?" Kaplan shouted as the crowd roared in applause.

In what had become an annual occurrence for the then-45-year-old veteran game designer, Kaplan stood on stage in a plain black T-shirt seated under an unfastened button-down shirt, with the Overwatch logo embroidered across the chest. After the announcement of Overwatch in late 2014 at that year's BlizzCon, Kaplan became one of the most beloved developers in the world. And now, he stood once again in front of a crowd chock-full of Blizzard fans eager to hear what he would announce as a part of the opening of the convention.

After his introduction, Kaplan threw to a video cinematic titled "Reunion" that featured release character McCree, a cigar-smoking, revolver-shooting cowboy, and revealed another character, Ashe, a female gunslinger who led a group of Western outlaws, including her sidekick, a large robot named B.O.B. In the cinematic, a gunfight between McCree and Ashe's Deadlock Gang ensued, emphasizing a past history between McCree and the group.

McCree came out on top, and in doing so, secured a white package.

From that container rose a white robot with a blue face and golden accents. Echo, she'd later be named, was revealed, but while Ashe became playable within hours of the cinematic, Echo remained dormant until a week and a half ago, with her release finally taking place on April 14.

In the weeks since Echo went live, she has had an immediate effect on Overwatch, which features one of the largest competitive game communities in the world. A damage-per-second character, Echo is able to inflict pain on opponents using projectile sticky bombs, a charge ray and ranged attacks. But the real fun is in Echo's ultimate, which allows players to clone an enemy hero and obtain their abilities, charge their ultimate at four times the usual speed and turn games based off adding to a team composition without the sacrifice of changing heroes.

Echo's release resulted in competitive balance questions around the game given her unique flavor among her fellow heroes, and within a week of her release, was chosen for Overwatch's competitive hero pool ban, which is based on how many people play as the hero as well as other metrics.

Overwatch's newest character is already one of the highest-played heroes in the game. But her origin story, from a development perspective, differs wildly from the other heroes in the four-year-old title.

Here's how Blizzard Entertainment built the game-changing AI, from the coding to the voice acting and building off player feedback.

Overwatch first spawned from Titan.

A massively multiplayer game, Titan was in development at Blizzard from 2007 up until May 2013. Known for its MMO genre games such as World of Warcraft, Blizzard set off to create a sci-fi game where players could either participate in deathmatch-style shooting or remain passive in noncombat professions, according to a 2014 Kotaku report. But with continuous delays far exceeding an internal project scheduled release in 2010, Titan was cancelled, and more than 40 of its developers pivoted to create Overwatch.

Echo, or some form of her, existed in the remnants of Titan, Overwatch lead designer Geoff Goodman said.

"Some original artwork that didn't look exactly like she looks now but was certainly very close and inspired to what she looks like now was originally created all the way back in Titan days," Goodman said. "Everyone really liked that concept way back then, even going into Overwatch, so we always thought that she'd be a really cool character someday in the game. And even then, we weren't sure she was going to be a playable character; we just liked her. You know, the art really at that point is all there was for the character."

Provided by Blizzard Entertainment

As the studio continued to design Overwatch's heroes, it became fascinated with the idea of having an artificial intelligence character and the concept of a hero that would attach to their allies, akin to the likes of Yuumi in League of Legends, but with the ability to become a turret. The team struggled with understanding how it would work such a character into the framework of Overwatch without making a mess of the game's meta.

How would other heroes heal that character? How would they ensure balance when it could attach to some like Tracer, who has outstanding mobility relative to the rest of the cast? Goodman & Co. conceptualized Echo as a support, but as they ran into more and more questions about how she would fit in the Overwatch universe, they eventually shelved the idea and moved on to making other characters.

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When Echo was revealed in the "Reunion" cinematic, the game team still didn't have a complete idea of what she would be. In the cinematic, they'd leave her character ambiguous, using Blizzard employee Lauren Tom as her voice actor in the initial rendering and preventing Echo from making any visual cues that would lock the team into game design requirements.

Goodman's group circled back and playtested a character with the attach ability, as well as the cloning ultimate. The latter made it into the game with some adjustments, while the attaching skill cut because of negative feedback about how difficult it was to counter.

At first, Echo cloned her allies. That, plus the attachment, was a major problem for opponents.

"It felt pretty oppressive," Goodman said. "You would like attach to your Genji and then wait for him to get his ult; then you'd ult him. So then you'd become a Genji with your ult also. And then you'd both ult at the same time, and it was like, 'How do we stop two Genjis dashing around our team?' It's like impossible."

Echo was shelved once again by the development team as they struggled to find a way to make her competitively viable without breaking their game. The clone ability presented a tricky situation in terms of duration, the use of ultimates in a game that centers heavily around them and all the tech issues that would come with seamlessly creating a character that could, for a short yet meaningful amount of time, become another character, use those characters' unique abilities and then transform back into herself.

Overwatch developers continued to try to find a way to sort through the software coding in game while also ensuring that players both on low-end PCs and consoles could play as the character they wanted to develop, given the lower amount of RAM and processing power available to those players.

Unlike any character before her, Echo presented a unique challenge in that regard.

Echo's ultimate transforms her into a member of the enemy team with enhanced charge time on her ultimate that can be a fight-changer for her team. Provided by Blizzard Entertainment

Amid the grappling with hurdle after hurdle, the Overwatch community was left longing for Echo -- and it certainly did so. Overwatch fans wanted to play the character they saw in "Reunion." Once they decided to make Echo priority No. 1 on the character-building list, it took the Blizzard team roughly six months to make a version of Echo that didn't totally crush the competition, Goodman said. That process lasted all the way through this winter.

Next came putting a voice and lore behind the hero. Blizzard contacted the agent for Jeannie Bolet, a British voice actor based in Los Angeles. An actor known for mostly TV work and some limited video game and motion capture experience, Bolet auditioned for the part, sending Blizzard a few samples of her recording voice lines.

"The feedback I received was really detailed, kind of describing who the person is, the fact that she is AI but that they don't want you to be reading like you're AI," Bolet told ESPN. "They don't have a specific region she is from. They just knew that she would be of some Asian, East Asian heritage, even though she's AI. There was a lot of, 'Here's what we'd like her to be, but we also want you to be yourself.'"

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Bolet landed the job this January and nearly immediately get to work, attending L.A. Studios in the Burbank-Universal City, Los Angeles area for about a half-dozen four-hour sessions led by Blizzard casting and voice director Andrea Toyias. Bolet isn't a gamer, she said, but she studied up on Overwatch and was stunned by the hype around the game, which features many prolific voice actors, such as Jennifer Hale -- the voice of Ashe and one of video game's most renown voice actresses -- and Matt Mercer, the creator of Dungeons & Dragons show "Critical Role" and the voice of McCree.

Bolet wasn't given any kind of script or lines prior to her first session. Blizzard, a company known in game development for being tight-lipped, did not want any of Echo's abilities or story to leak. When she got in the studio, Bolet was shown cinematics of Echo, her origin story and some of her abilities that Goodman and his team were nearing completion with.

Soon, Bolet found out she'd need to repeat voice lines for every single hero ultimate ability in the game, including many in different languages and others originally spoken by men.

"For me, it was really exciting because I love doing accents," she said. "It's not often that I get to do that many. Some were actually quite difficult because I don't speak other languages. I speak English, I speak really poor Cantonese, almost nonexistent Vietnamese cause that's my heritage. But it's just a lot of fun to be able to repeat those lines phonetically, hopefully get them right.

"I do know some of the lines out there did rip up my throat quite a bit. Someone like Genji or Hanzo, especially because some are very masculine Japanese kinds of phrases that came out from their mouths."

Bolet recorded more than six sessions over a multiweek period, racking up more than 24 hours worth of tape. Toyias made her selections and in real time and showed Bolet which she liked the best, but the actress didn't get to hear her lines vocoded or with Special FX until she saw the release trailer for Echo on March 18.

Echo released on April 14, and Bolet admittedly hasn't played her but wants to spend some time as her character eventually.

"I love illustration and animation in general, so when you combine storytelling and this form of visual storytelling, I'm there, even though Overwatch to me seems like quite a difficult game for me to play, especially for someone who's not a gamer," Bolet said. "But I'm going to try. I'm gonna hop on at some point. I feel like I have to, too. Really, it is my duty."

Echo's impact on competitive Overwatch, resulting in the hero pool ban for competitive play, is clear already. Some call her overpowered, and Goodman said Blizzard is keeping an eye on the ultimate in particular and whether it needs to be adjusted or not.

Echo hasn't made her way to top-level competitive play yet, as she remains banned in the Overwatch League this week. But that hasn't prevented pros from diving into the new character and learning how she may impact the game at its highest level of play.

"It just depends on the hero bans for the week," said Houston Outlaws pro Dante "Danteh" Cruz, who took first in a recent Echo community tournament. "If the hero bans of the week enable her to be good, then she'll be very strong. But I think if heroes that enable her are banned and heroes that are good against her aren't banned, she'll be pretty weak."

The best complements to Echo, he said, are characters with "invincibility skills" or crowd control protection and those that can make the most of her four-times ultimate charge.

"Heroes like Mei, Reaper, Orisa with the fortify, you can block CC and stuff," Danteh said. "Heroes with a strong ultimate too, like Reinhardt, where you can drop down with the Shatter above their supports and get Shatter in two swings."