Shades Of Magic Vol. 1 by V. E. Schwab

The Steel Prince

In a world where parallel Londons exist, each with its own unique magic system, a rare magician named Kell serves as an ambassador and smuggler between the realms. His life takes a dangerous turn when he inadvertently becomes entangled in a perilous plot involving a forbidden artifact from the darkest of the Londons. As he navigates the treacherous politics and power struggles of these interconnected worlds, Kell must ally with a cunning thief named Lila to prevent a catastrophe that could unravel the very fabric of reality.