Kwai is a minor antagonist in Rick Riordan's novel The Throne of Fire, and one of the secondary antagonists of The Serpent's Shadow. He is an exiled magician from the House of Life who is now a rebel.
The Throne of Fire
Kwai was one of the rogue magicians hired by Vladimir Menshikov to launch an assault on Brooklyn House. He and Sarah Jacobi lead the assault, only to be defeated by Carter and Sadie when they come onto the scene. Kwai and the other rogue magicians are forced to retreat.
The Serpent's Shadow
Kwai works together with Sarah Jacobi to rally the magicians of the House of Life against Amos Kane, who is the new Chief Lector. Jacobi and Kwai turn or kill most of the Kanes' allies. They also send a message to Carter threatening him to surrender.
Jacobi and Kwai lead an attack on the First Nome while Apophis rises to devour the sun. Kwai, Jacobi, and the rogue magicians almost defeat Amos, who is channeling the power of Set to fight the rebels. Carter, Sadie, and Walt enter the Hall of Ages to help Amos. They kill Jacobi and mortally wound Kwai. With his dying breath, Kwai reveals that he and Jacobi were following Apophis' orders. He casts a destruction spell on the Hall of Ages right before he dies. Luckily, Sadie is able to cast a powerful spell that counters Kwai's.
- Kwai - Riordan Wiki