Legacies - The Sublime is a sourcebook for Mage: The Awakening. It details numerous legacies, specialized paths available to Mage characters.

Summary
From the Onyx Path catalog:

"Time is a cycle.
Beginning.
Middle.
End.
All part of the cycle.
Genesis mandates conclusion;
a start necessitates a closure.
The tims is nigh for the conclusion.
This is the end."
-- Durandal, prophet of the Cult of the Doomsday ClockMages aspire to greatness, and none more so than those who craft their souls with the techniques of the sublime—legacies that invoke awe and terror. Legacies: The Sublime details 13 all-new legacies, the specialized magical paths that result from soul-shaping and grant unique mystical attainments. Each legacy features a detailed history and organization along with its own unique attainments. Legacies: The Sublime also provides complete rules for designing your own legacies.160-page supplement for Mage: The AwakeningThis book includes:

13 new legacies for players to choose from
Extensive advice for players and Storyteller on creating their own legacies
Two all new "techgnostic" legacies, for mages who mix magic and technology.