Your destiny as The Listener is far greater than any before you. Sithis has seen your heart. It is bathed in blood, and hungers for more. So he has granted you his Boon.
In The Warden Chest in Helgen, Sithis has left you a gift. Four gifts in fact.
To help you slay your enemies and send their souls to The Void, Sithis has granted you two Blades of Woe. But that is not enough. To help you kill silently, Sithis has granted you the Sithis Ring of Sneaking. However, The Blade of Woe is weak. It is not a true weapon of assasination. Thus Sithis has also granted you the Sithis Amulet of Destruction.
With all equipped, every single foe will fall before you. And they won't even know you're there.
However, there is more.
The Sithis Amulet of Destruction also greatly empowers Vampires, making them infinitely more deadly. Wipe out entire legions of soldiers single handedly..
And, if that wasn't enough, The Sithis Amulet of Destruction also greatly empowers Destruction Spells. Unlock Firestorm, and you can burn entire armies to the ground in seconds.
The power of Sithis is finally completely at your disposal.