Riot Games released a new trailer video this week that shows a behind-the-scenes look at how the game art is made. The video features the designers behind Irelia’s rework and reveals an intimate look at what it takes to produce the visual art, audio, and gameplay balance for a character.

League of Legends product manager Michael Chu says it can take a few months before the designers are even sure they are taking a rework in a good direction. Each new champion kit is evaluated based on why they are chosen by players. For Irelia, the most critical factor was her Bladesurge.

Development manager Ford DeCastro says the team started with Irelia’s passive. They used Player Labs, or evaluations of average players who test champion reworks in the studio, to determine which changes will work for the character. Occasionally, the team brings in more famous gamers to test a champion in their Players Labs.

For this particular rework, the team brought in notable Irelia main “Irelia Carries U” to test their changes. Based on his suggestions as well as the comments they received from other players in the lab, the team compiled the Irelia update that is now available in the game.

In the video, developers described how the character was not fulfilling the fantasy implied by her in-game actions. Though they were nervous to unveil their character kit designs to players, they said getting opinions from outside the development studio made all the difference in Irelia’s design.