The Atlas Paradox (Atlas Series 2) by Olivie Blake

Six magicians were presented with the opportunity of a lifetime.
Five are now members of the Society.
Two paths lay before them.

All must pick a side.

Alliances will be tested, hearts will be broken, and The Society of Alexandrians will be revealed for what it is: a secret society with raw, world-changing power, headed by a man whose plans to change life as we know it are already under way.