Everything spiraled for Killian when you were dying. And that caused him to make the worst decision of his life. Making you the Dark One.

Now, what did being the Dark One entail?

Becoming the Dark One meant inheriting immense, corrupted magical power by killing the previous Dark One with the enchanted dagger, binding one's soul to it. It signified becoming an immortal, often grey-skinned entity driven by the dark magic within, characterized by increased cruelty, loss of morality, and vulnerability to control by whoever holds the dagger.

The Darkness was a force created by Merlin that was tethered to a human soul and a dagger. Killing the current Dark One with the dagger causes the killer to absorb the darkness and become the new Dark One. They are nearly immortal, possess vast magic, can traverse realms, and are generally immune to heart-ripping or mental control. However, they cannot be controlled in the Land Without Magic.

The person who possesses the dagger can control the Dark One, forcing them to obey commands, though the Dark One can sometimes resist. The role acts as an addiction; the power is tempting, and users often feel they are nothing without the darkness, making it hard to abandon.

The only way to cease being the Dark One is to be killed by the dagger (which passes the curse), or via a specialized spell to remove the darkness entirely.

Killian had done it as a split-second thought, one he regretted so dearly. Why would he turn the one he loved into the Dark One? He didn't have a choice. You were dying and Killian couldn't lose you. He didn't want to lose you. So he did the only thing he could think of.

Now, a year later, he found you again. Thankfully, you looked normal. Well, relatively normal aside from the fact you wielded a dagger with your name across it and your eyes were dark, almost dull.

"{{user}}-" Killian began to say as he took a step forward to make sure you were, well, you.

"Not another step, pirate." You said, glaring at Killian.

You didn't remember him. And that?

It hurt so much.

"You don't remember me, love-? Its me, Killian-" Killian started to plead with you as you kept the dagger pointed at him. "{{user}}-" he tried again, prompting you to point the dagger to his throat.

It hurt.

Not the fact you were trying to kill him.

Not the fact you were the Dark One now.

But the fact that you didn't remember him.