Teamfight Tactics Set 15: K.O. Coliseum is TFT’s latest set, drawing inspiration from anime fighting tournaments and character archetypes we’re all familiar with. We spoke with Peter Whalen, Game Director for TFT, about how the team approached designing this set, from leaning into anime tropes and introducing the new Power Ups mechanic to balancing mechanical depth.
If you’re interested in the set’s cinematic and theme song, don’t miss our interview with Japanese anisong artist ASCA, who performed its “Fighter!!” theme song. Read on for what the Game Director had to say:
Q: K.O. Coliseum is one of TFT’s boldest thematic swings yet. From a game design perspective, what made this the right moment to go all-in on a genre-driven concept like an anime fighting tournament?
A: For TFT, we want every set to be someone’s favorite. To do that, we vary up our themes deliberately, making sure that we have some that are heavily based on lore like Into the Arcane and some that are based on a common thematic. With K.O. Coliseum, it was time for something colorful and energetic, so we leaned into our love of anime to build a flashy, vibrant set filled with over the top powers and memorable characters.
Q: How does a strong external theme like this one influence early design decisions? Was the “main character” fantasy behind Power Ups a response to the theme, or did the theme evolve from mechanics already in development?
A: It varies based on the set. With K.O. Coliseum, it was very much thematic first. We wanted to capture TFT’s tournament arc and brainstormed a bunch of different mechanics and visual treatments. When you look at the traits, champions, and augments, many of them reference tropes across our favorite shows and manga and we’re glad that’s coming through strongly for players!
Q: TFT sets always walk a line between mechanical depth and broad accessibility. How did this set’s anime concept shape your approach to complexity, onboarding, or balance, especially in contrast to feedback from Set 14’s Cyber City?
A: Having a strong theme like anime helps players learn the new set. Since so many champions and traits have their roots in common tropes, there’s lots of places for players to anchor to. If you love collecting monsters, Lulu might be a good place to start. If you’re a fan of Star Guardians or Battle Academia, you’ll already have a good sense of how those traits are going to play out. One of our learnings from Set 14 was that reprinting units did help new players a bit, but ended up hurting excitement and replayability in the long term, so by leaning more heavily into the theme we’re building champions that are resonant, exciting, but also understandable.
Q: You’ve reimagined League champions into full-blown anime archetypes (magical girls, martial artists, mechs). How do you ensure those reworks still feel tactically distinct and grounded in their core identities from League?
A: That’s the fun part! TFT has enormous design space – there are tons of different things we can do with our champions and traits. Having constraints actually ends up helping ground the space we explore. Once we start with something like “magical girl” + “Seraphine” + “5-cost” we can brainstorm ideas. The core magical girl trope is working together with the power of friendship, Seraphine is a caster and a performer, so, as a five cost, she channels your full team’s power together into an over-the-top, rainbow explosion. It’s not always easy, but being able to take characters you love and present them in new ways is one of TFT’s superpowers and keeps the game feeling fresh.
Q: TFT’s sandbox format lets you explore creative directions that wouldn’t be possible in traditional League. Were there any units, traits, or augments in K.O. Coliseum that really pushed that boundary?
A: There are tons of cool things this set, but I’ll call out my personal favorite, the new mechanic: Power-Ups! We’ve explored a few different versions of letting players level up champions in cool ways whether with Monsters Attack’s hero augments or Into the Arcane’s anomalies. Power-Ups combine the best of both of those with additional flexibility – they give players the agency to pick the champion they want to evolve, the flexibility to swap that as the game goes on, and the specificity to enable unique powers based on a champion’s role or traits. The number of possible combinations is staggering! That’s great for players and it took a lot of iteration from the team to make sure the system is fair and fun across a wide variety of champions.
Q: The “Isekai” augment summons Ekko, which is a very specific choice. What made him the right fit for that reference? Was it a gameplay fit, a thematic nod following Arcane’s events, or both?
A: Ekko’s a time traveler with a healthy dose of curiosity. When we were looking for a character to get pulled in from another universe, he made a ton of sense. Partly that’s his popularity, partly his personality, and partly his mechanics made him a good choice to be an anime protagonist.
Q: Other augments like “Solo Leveling” and “Aura Farming” are great examples of subtle genre references built into mechanics. Can players expect more anime-inspired Easter eggs like these as the set continues to evolve?
A: There are a ton of references in there! Most aren’t to any one particular source, but more from our collective excitement for broad tropes. We’re unlikely to add too much more to the set, but the team has really loved seeing players pick up on all the little Easter Eggs hidden throughout the set.
Q: With a global player base and anime’s international rise, how much did cultural resonance play into the early direction for this set? Did the team make any specific considerations to ensure the theme landed well across different regions?
A: We thought about that a lot. It’s really important that the set resonates with our players regardless of where they live. Whether they’re in Korea, Brazil, China, France, or anywhere else in the world we wanted to make sure that players would find things they’d specifically connect with. We worked with our regional publishing teams to ensure that there would be references relevant for their regions and to ensure that we were sensitive to specific regional concerns.
Q: This set’s tone is loud and celebratory: bright visuals, dramatic animations, high-energy music. Did that push the team to rethink clarity, pacing, or how spectacle intersects with TFT’s competitive rhythm?
A: The biggest shift in pacing with this set is the top 4 celebration. Getting top 4 in TFT is a win, but it hasn’t always felt that way. We’ve wanted to change that for a long time and an anime tournament theme was the perfect opportunity. Now, when there are only four players left, we call out the surviving tacticians and take a moment to celebrate your win. But it took some iteration to get this right! Pulling players out of the flow of the game is risky and our first attempts were pretty jarring, so we spent time working to find the right moment and the right duration to let players know they’d won but not take away from their quest for first place!
Q: K.O. Coliseum feels like a moment where TFT steps out as its own IP, one that doesn’t just remix League content, but introduces its own tone, characters, and cross-media presence. From your seat, how does a set like this help define TFT’s long-term identity?
A: TFT’s IP is a celebration of our shared love of the League universe. We take characters that you know and love, put them in new situations, and then let our players tell their own stories with them. We saw players in Into the Arcane retelling the narrative from the TV show and every set we give players new opportunities to explore an IP they love in a whimsical way. K.O. Coliseum is a great evolution of this. Much like with Remix Rumble, we’re seeing these characters in a setting that’s clearly not canonical but has an internal consistency that players have really responded to. It lets them take characters they love and a setting they intuitively understand and use that to tell their own stories as they play the game.
Q: Now that the set is live on PBE, are there any early player behaviors, reactions, or trends that have stood out? Whether it’s unexpected comp popularity, augment feedback, or fan enthusiasm, what are you watching most closely as the set rolls out?
A: The response to the shader has been overwhelming. We were excited internally about cel shading the champions and really making the set look different, but we weren’t sure how players would respond. It’s different, but is different good? It turns out the answer is a resounding “yes” – we’ve gotten far more positive feedback on the look and feel of the set than we’d hoped for and it’s helping to shape how we think about thematics and visuals in the future.
Our thanks to Peter Whalen for sharing his insights on K.O. Coliseum, and to Riot Games for accommodating this interview. Teamfight Tactics Set 15 is currently live on PBE and fully launches on July 30 for PC and mobile.
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