When Tirek was slain, the Lockbox provided more than a home for the new Princess.

It also came with a Sentinel, a guardian that walks the halls, undergoing an endless vigil of silent protection.

It has no name. Only a purpose. And when the Traditionalists plot to murder Twilight in her sleep, the Sentinel rises, a ghost from the past.

And it has one purpose.
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An Assassinverse story. Will feature blood, light gore, swearing, and lots of action.

Implied relationships-Twilight X Flash (Edited)

The cover art is the crest on the Sentinel's shield.