The effect was made by Digital Artist DDDDDD.
Chinese VFX Artist known only as DDDDDD unveiled a new stunning visual effect with strong Arcane and Borderlands vibes. This time, the artist set up an awesome stylized attack FX with colorful slashes, picturesque explosions, and comic book-like sound effects symbolized by words. According to the project's description, the effect was made using exclusively Unreal Engine.
And here are some of the artist's earlier works: