Witching Cloak

The Witching Cloak was an immensely powerful magic cloak. It was later revealed that the Cloak itself was originally crafted from Mr. Dark's Bag of Endless Nightmares and Infinite Screams, a tool personally created by him using his own essence which due to him being one of the Great Powers, gave the cloak its immense magical powers and abilities.

Creation
At some unknown point, Mister Dark created the Bag of Endless Nightmares and Infinite Screams to hold naughty children. After being imprisoned by the Boxers the Empire took his sack and made the Witching Cloak from it. Unknown to the Empire, the cloak was a part of the Dark One and he used this connection to subtly suggest the wearer towards a series of events to free himself.

Fabletown
Boy Blue was assigned the task of testing it's capabilities when he first donated it to the Fabletown vault. He previously was given it by Colonel Bearskin as a means to escape the battle at the Last Castle once the enemy overpowered them. When the final resistance fell, Boy Blue used it to teleport himself onto the final ship out to the Mundy realm.

It was later used by Boy Blue during his infiltration of the Homelands. He managed to sneak his way through the Adversary's forces by taking on different forms.

The cloak was a catalyst in Boy Blue's death as well. While wearing the Cloak, Blue tried to block a magic arrow from hitting Bigby. As the arrow was enchanted to always hit it's mark, it negated the cloaks protective barrier, traveling straight through Boy Blue's arm, to hit it's target. A piece of the cloak became lodged inside Boy Blue's body, and it made him gradually weaker until he passed on.

Shortly after Mister Dark's reawakening, the Witching Cloak disintegrated and vanished, it's magic having been drained into his person.

Effects
While wearing the Witching Cloak, the user can make themselves invisible, as well as change their form to almost whatever they desire. The wearer is also able to teleport across distances and dimensions, as long as they know where they want to appear. The cape is nearly indestructible, though other magic, if strong enough, may cause some harm.