I am going to do something stupid.

"You're leaving?" Shikaku asked.

"Not forever. Hopefully."

"Hopefully?"

"I intend to come back, Shikaku. But there is a not inconsiderable possibility that I simply won't return."

"Do you mind if I ask why?"

"Why I might not return, or why I am leaving?"

"Both."

"The answer to the first ties into the answer for the second. I might not return, because the place where I am going it not a place to be taken lightly. I am leaving, because the place where I am going is also the place I need to go."

"And why do you need to go there?"

I shifted, uncomfortably. "Let's just say... there are bad things that can occur, and I would rather like to have the ability to do something about them. But those aren't things that you need to worry about. And probably won't be things you'll ever need to worry about."

"Hmph, troublesome."

"Leaving?"

"Hopefully not permanently. But yes, I cam to told you that I might not be able to visit you."

She nodded, a bit sad. "Is there anything I can do to help?"

"Not that I can think of. But thank you for the offer, Madoka. "

I had never been to the Realm of Darkness before. I had skimmed it, sampled the outermost edges of that dark place, lingered just on the other side of border of the Realm Between and the Realm of Darkness, but I had never truly gone into the Realm of Darkness itself.

It is, perhaps, strange; that a creature of the purest Darkness like myself, a Heartless, had never been into the deepest depths. The reason why was simple, in that I didn't have a reason to go there.

I'd been living inside a World, with the Nara. Why would I want to go to those dark depths?

Why would I want to go there, where the Darkness that I devoured, and attempted to devour me, existed?

Well, I had a reason now.

Something that I had been putting off for months, perhaps for good reason, perhaps out of cowardice. I had tasted Darkness, and that taste was a terrible, terrible thing. Even the amounts I drew upon and tasted, took, and turned into Me, such amounts were infinitesimal compared to the Darkness down there.

It was caution, perhaps for good reason, perhaps for cowardice.

But it was something that I could no longer hold back on.

The fact of the matter is, I needed to go down there now.

The incident, months ago, when the other Heartless had nearly come into being...

It was going to happen eventually.

The Heartless would eventually come, in force. The Dimensional Barriers of the Worlds, all of them, would eventually fall, and open the World and its inhabitants up for the feast. I could kill and absorb countless Heartless, but I couldn't protect all of existence simultaneously from the endless hordes. Nobody could.

The Heartless were infinite. So long as there was Darkness, there would be Heartless. So long as there was existence, there would be Darkness. There were uncountable Worlds, and nobody could protect them all.

Not me, alone.

Not even a Keyblader could protect them forever. Not one, alone. Not ten, together. Not one hundred, not one thousand.

Not 10,000 or 100,000.

Because Darkness was just as insidious as it was powerful. And Darkness possessed no limits on its power.

But, there was something that I could do, that a Keyblader could also do.

Mitigation.

I could do it only one way. Keybladers could do it in two.

Both a Keyblader and I could destroy a Heartless. Truly, totally, finally, utterly Destroy a Heartless, not just send it back to the depths of the Realm of Darkness, but render it gone, permanently.

A Keyblade could destroy them. Me.

I, however, could absorb them, add their Darkness to my own and grow that much more powerful.

The methods were different, but the end result was the same.

Either way, however, that couldn't solve the problem by itself. We could destroy and destroy and destroy, but the Heartless would still come.

There was nothing I could do about that. Nothing the Keybladers could do about that.

But the Keybladers...

They had another option.

Hearts were what drew the Heartless, like moths to a flame. None more so than the Hearts of Worlds, which were like burning stars compared to the flickering candles of the Hearts of people.

The Keybladers could lock away such a Heart, sealing the Keyholes and preventing the Heartless from devouring it. Unable to get at such a Heart, the vast majority would leave, drawn to the Hearts of other Worlds, though some would stay to prey on the Hearts of the people who inhabited those worlds.

Such an option, such a solution...

It worked.

It also simply wasn't viable.

There were countless Worlds. Seemingly numberless. Not literally numberless, but the number was so close to it that the difference was academic at best, to any single being.

Unless you were a being of Darkness. Because Darkness was infinite, and Darkness was everywhere, and where there was Darkness, so too would the Heartless never be far behind.

When the Heartless came, and they would, they would siege each and every single World across all of existence, simultaneously.

Only the barest fraction of a barest fraction of a barest fraction of a barest fraction of those Worlds would be lucky enough to have a Keyblader seal the Keyhole to the World's Heart. The rest... would be devoured. The inhabitants with strong Hearts cast away, to other Worlds, and if they were exceedingly lucky, they would land on one that had been visited by a Keyblader, with its Keyhole sealed.

After having lost everything, their friends, their family, their possessions, everything they had ever known and loved.

There were people who had broken utterly for less.

No, sealing the Keyholes couldn't prevent the Heartless from devouring everything. It would only 'work' to prevent the Worlds themselves from being devoured. It did nothing to help the people of those Worlds, because the Heartless would still be coming, just in lesser numbers.

We, the Keybladers and I, could mitigate. But we couldn't stop it from happening, merely slow it down. No matter how hard we tried, now matter how quickly we worked, we could never stop it.

It was... a very harrowing thought. A terrible, terrible thought, that countless worlds and countless more people were going to die, and there was almost nothing I could do about it.

I didn't like it one bit.

In fact, I hated it completely.