Power of waking

"What do you think the power of waking is? It's for traversing hearts to reach worlds. Not for traversing worlds to reach hearts. There's a high price to pay for wielding such power foolishly."

—Young Xehanort, to Sora

The power of waking (眠りし心を解放する力, Nemurishi Kokoro wo Kaihō-suru Chikara, lit. "Power to free a sleeping heart") is an ability introduced in Kingdom Hearts 3D: Dream Drop Distance, and is a key plot element in Kingdom Hearts III. It is described by Yen Sid as "the power to free a heart from its sleep".

Only Riku, King Mickey, Aqua, and Sora are known to posses the power of waking.

Abilities

True to its name, the power of waking is able to awaken a sleeping heart.

The power of waking can also use hearts as an intermediary to travel to certain worlds. It can additionally be used to reach the Realm of Darkness, and is one of few ways to do so outside of using a Corridor of Darkness, or a world becoming unstable.

Unintended uses and consequences

However, the power of waking has unintended uses - since the states of sleep and death are connected, it is possible to use the power to restore recently-deceased hearts. Furthermore, the ability to use hearts to reach worlds can be reversed, instead using worlds to reach hearts.

Abusing the power of waking in these ways is a "nature taboo", and incurs a high price for the offender - their power of waking will be revoked, as well as some of their other abilities, and they will vanish from the world where they originate. As a result, the offender will be unable to return to their original world without outside assistance.

Story

Kingdom Hearts 3D: Dream Drop Distance

Sora and Riku take a Mark of Mastery exam to not only be named Keyblade Masters, but also obtain the power of waking by awakening the Sleeping Worlds. However, Sora loses this power when Xehanort corrupts his heart with darkness. After passing the exam and defeating Xehanort, Riku uses the power of waking to dive into Sora's heart; there, he defeats the Armored Ventus Nightmare and awakens Sora by answering three questions in a vision of the Destiny Islands.

Kingdom Hearts III

Sora travels through the worlds in an attempt to regain the power of waking. Upon facing Vanitas at The Land of Departure, Sora realizes with Ventus's help that the power of waking is still sleeping within him. He then uses the power of waking to free Ventus's heart from within his own and awaken him from his eleven-year coma.

After rebuilding his body in The Final World, Sora uses the power of waking to travel between facsimiles of the worlds and track down his friends' hearts, in an attempt to save them from the Lich. He succeeds and sends them back in time to their arrival at the Keyblade Graveyard. As a result, Sora creates a tear in the fabric of time known as a singularity and changes history so that Sora's friends are saved by the Lingering Will.

Kingdom Hearts III Re Mind

After the final battle with Xehanort, Sora travels back in time to before his arrival at Scala ad Caelum to save Kairi's heart. He succeeds, but having repeatedly used the power of waking to restore hearts that have been erased from existence, Sora vanishes into another world.

Kingdom Hearts Melody of Memory

After a year of searching for Sora after he disappeared, the Fairy Godmother takes Riku and Kairi to the Final World, where they meet the Nameless Star. The Nameless Star opens a Portal to the world of Quadratum, and Riku uses the power of waking to travel through it.