EXCLUSIVE — The VFX Artist Behind League of Legends Swarm

Senior VFX artist Kevin Leroy (aka Sirhaian) shares his experience working at Riot Games, serving millions of players.  

We had the honor to sit down with Kevin Leroy for a chat. If you're not familiar with Kevin's work, he first gathered the attention of the VFX team at Riot when he made a series of fan art visual FX animation for League of Legends created in Unity starting as early as 2016. We featured one of his effects with a full break-down on our YouTube channel.

Since getting his foot in the door with those early fan art VFX, Kevin has gone on to an impressive career at Riot, pursing his passion of making some of the most iconic and dazzling visuals in the game.

Recently, an amazing turn of events happened when Kevin, a VFX artist by trade, became a game designer and created an early prototype for what would later become the massively popular Swarm game mode for League of Legends. Kevin is a good friend of ours at VFX Apprentice, so we wanted to sit down with him and ask some questions about his journey as a VFX artist, and now a game designer.

Image: Some of the intense action featuring insane amounts of VFX in the new Swarm game mode. 

Hey, Kevin! Tell us a bit about your origin story. How did you discover VFX as a career path, and what was interesting about it to you in the early days? 

Kevin Leroy:

Hi! I started getting interested in VFX back when I was in graphic design school. I chose the “Games Art” path, which was more environment focused, and one of our teachers explained how he had to cheat visuals in some of the games he developed a long time ago. The idea of creating visual effects using smoke and mirrors really appealed to me, and that’s how I started looking into VFX as a discipline. We also had to create a 3D environment for our exam, and I realized I was having more fun creating the VFX for it than making the environment itself. After that, I participated in the 2014 Riot VFX Art Challenge, and while I didn’t win (not even close lmao), I did get contacted by an indie Italian video game studio (Rimlight Studios), and got hired. I moved to Italy for the job and that’s how my industry journey started!

Image: VFX artists like Kevin play a major role in signaling clarity for the gameplay, while delivering powerful satisfaction to players.

Could you share some of your highlights with us? Maybe a few favorite skins you've worked on, or stories from work that really stand out to you as happy memories.

Kevin Leroy:

Oh my, there are a lot! If I had to choose a couple, I’d start with Dark Cosmic Jhin. I LOVE space and when I heard I was gonna get to work on a space themed-skin for Jhin, I was ecstatic! I immediately started prototyping some ideas for his ult and got the approval to go a little bit crazier by using some stencil tech to show a space background in his R cone. The entire production was a big collaboration across all the disciplines, and I still fondly reminisce on those times today. Another one I really enjoyed working on was Mecha Kingdoms Jax. This was actually one of the skins I wrote the most code (script) for. I wanted it to be perfect. The team let me run wild with ideas for it, such as adding the first evolving Kill Counter emote for his Taunt or giving him a Damaged state where he shoots sparks when below a certain health threshold. Oh, and I really enjoyed collaborating with one of our designers on his Dodge spell: in this skin, he zaps the projectiles he dodges instead of just letting them hit him. That was a super fun experience all around. I just really love experimenting in our engine. We have quite a few limitations (tech, gameplay, readability, art style, etc.), but those limitations always unleashed creativity instead of limiting it! 

 Image: Dark Cosmic Jhin is one of many skins Kevin Leroy (aka Sirhaian) has worked on.

What is working at Riot like? How is it the same as you imagined before you worked there, and how is it different?

Kevin Leroy:

Well, I was (and still am!) a big fan boy back then, haha. I had worked at a couple other studios before, but nothing even came close to Riot. My main surprise was the feedback culture. Receiving feedback always feels like I’m being given a gift: I can accept it or politely decline, but I know it comes from a good place, and in the hopes of improving the product or helping the artist. The feedback culture is very healthy, at least in my experience. I’ve also not noticed any competition between people. Instead, everyone tries to elevate each other. Riot is definitely not perfect, but I do feel it’s a good place with amazing people. Also, we have great food. 

Image: Inside the Riot Games office in Los Angeles. 

Can you share the story of how Swarm came to exist?

Kevin Leroy:

So, I’ve kind of always been interested in design, even back at school. I remember having fun creating triggers in UDK (the predecessor to Unreal Engine) with Kismet when players passed by certain objects. Good old days! But even at Riot, ever since I was taught how our scripting tools work, I’ve been trying to use that knowledge to improve our skins. I scripted the first kill counter emotes, Pentakill celebrations, reactive shields and many other Legendary skins features. It just felt like a game to me in a sense?

At some point, I wanted to learn more about our engine in general - not just for skin features - and I started creating a sandbox after hours on my laptop. I kept bothering designers and engineers left and right to let me in on their secrets and I tried my best to soak in all the arcane knowledge of how the League engine functions. After a while tinkering on my laptop, I realized I could try making a little game mode to test my knowledge. I started by spawning a few minions repeatedly and triggering a win if you survived for a minute. I built upon that foundation and ultimately got a functioning horde survival prototype with XP drops, items to pick-up, and several different waves of enemies.

Check out some of the incredible VFX from Riot's new game mode, Swarm:

Eventually, I made a pitch to senior leadership explaining the potential of this new game mode and how it could be brought to players, as well as a demo of the prototype and everything I learned from it. In those discussions, my leads explained how difficult it would be to make PvE for League, as the engine was never made for that. And to their credit, the prototype clearly showed those short-comings: it was laggy, hard to control and bug-prone. We also talked about the performance and issues of the previous PvE projects that were done in the past, such as Odyssey: Extraction and Star Guardian: Invasion. The community loved these, but they only played for a few days, after which most people stopped playing entirely, despite the high investment. We all agreed it was best to not push forward at this time.

A few months passed and at some point, I was watching a video from Necrit, a YouTuber who talks about League and its lore. In that video, he talked about how he really wanted us to bring back an experience similar to Odyssey: Extraction, with some randomness added on top and roguelite elements. I thought to myself “PvE with randomness and roguelite?” This was pretty much exactly what I had built!

Image: Battle Bunny Aurora is featured in the new Swarm game mode. 

I went back to my cave and worked on the prototype again, this time with more polish and a few new features, and when it was ready, I proposed it to two members of the team, Riot Naxt and Riot August who were actually working on pitches for a very similar concept. Funnily enough, no one knew that the three of us were doing the same thing! So the three of us transferred the project from my laptop to our internal, shared dev environment. We got some more people to test it and eventually, it reached the ears of leadership again. We were given a couple months to officially work together on my very unofficial prototype to polish it up and pitch it as an official project to the team.

Ultimately, it got greenlit and we got a full team. I left the Skins team and moved to the Gameplay team to fully focus on this new project. We had to fully rebuild the game from the ground up (turns out spaghetti prototype scripting isn’t the best for a fully funded project, haha) and built a bunch of new tech to be able to fully support it for the Anima Squad event.

Image: Rek'Sai makes a formidable boss in this co-op PvE game mode. 

How has it felt watching the success of the Swarm game mode? What is the energy of the team right now watching this come out, and how are you personally feeling?

Kevin Leroy:

Well at the time of writing, it has only come out on PBE (Public Beta Environment), but it has been extremely energizing to see people's reactions to it! I’ve been seeing people playing it continuously on PBE despite having fully completed the game already! But I am still very stressed out about the release, and I really hope players like it. The entire team has poured sweat, tears and their hearts into this project. I really want it to be a success so we can show that PvE has a place in our League ecosystem.

Image: Chaos and intensity escalate as each round progresses, throwing increasing amounts of enemies and visual FX on to the screen.

Now that you've helped create a new game mode, are you interested in pursuing game design further? What options are available to you as a senior VFX artist, and what gets you excited to come into work?

Kevin Leroy:

Yes, I am very interested in exploring design further! It is a bit of a complex topic, so I can’t go too much into details here, but my personal dream would be to continue doing what I do now: working on design for new game modes and making VFXs for the designs I create. I just find it… fun! Doing both VFX and design just sounds right to me. 

What gets me excited is the ability to test completely new things out and find new ways to delight players. It’s a very cliché thing to say, but that is what keeps me going! I’m also a player, so it is also sometimes about finding the next thing I’d like to see. 

A lot of people reading this article are considering a career as a VFX artist. What would you like to say to these readers?

Kevin Leroy:

First of all, best of luck to you all! The games industry isn’t easy, especially right now, but VFX is exceptionally fulfilling. You get to do so many cool things and collaborate with so many different disciplines. You get to do a bit of animation, a bit of physics, a bit of painting, a bit of modeling, a bit of scripting… and so many other things. It is super fun and well worth the time. I would recommend watching a bunch of tutorials to learn the ropes, and experiment on your own to find your own style and preferences. One great thing is that this website offers top-of-the-line tutorials and courses for many different topics about VFXs and I couldn’t recommend it more. We also live in a time where VFX tutorials are varied and easily accessible on YouTube or forums as well. I personally have found that doing fan arts can also be very useful! It helps teach you a style and techniques you might be particularly interested in, and it’s often fun to see and share your results as well! A studio seeing that you can replicate their art style on your own might be more inclined to hire you. Whatever path you decide to follow, remember that you are not alone. The VFX community is big and very welcoming. It will be hard and you will be tested. The games industry is sadly not all just games and laughs. But if you persist, you will find your way, and get to bring smiles to players around the world. 

Thanks again to Kevin for taking the time to answer these questions. And thanks for the amazing work you've done for our community. We look forward to seeing all the impressive visuals and design work you'll be making in the future. Take care!

All Images via Riot Games