No, I'm not someone who has studied the mind or whatever, so don't pick this a part if you happen to be. This is just how I feel when I 'pick at a scab' that doesn't hurt… And it's how I imagine Morgana feels about her newfound evilness. If I confuse you, don't worry, I spell out what I meant by each metaphor at the bottom.

If you pick at a scab and pick at it until it finally comes loose, it hurts. But it brings a strange satisfaction with it, the satisfaction that keeps you picking at those scabs. And if you don't pick too much or too little, the day comes when you peel away the hard covering and find no wound underneath. You've healed. And there's one more scab you never have to look at again.

But what if there was no pain? What if you kept picking and peeling at that stupid red covering, but you couldn't feel it pinch and pull at your skin? That would not be pleasing. Rather, it would be frustrating. You would glare at your injury, wishing you could at least know it hurt, wishing that not something you did had some effect. A very aggravating feeling, one that would make you want to scream. Yet, at the same time, it would feel a little, itty bit good. Because there was no pain.

Like numbness, there would be no pain. But there should be.

Now imagine that scab was your heart, totally dead, only existing to pump blood. You keep picking and poking at it, half-hoping for some result and half-hoping you'll feel nothing. It angers you. It gladdens you. It makes you feel totally indifferent. But, in a strange way, you find it infuriating. You can't even make your own heart respond as you once wanted it to. Eventually in a fit of temper, you grab at something long and sharp – say, a dagger – and totally insane by now, you attempt to drive it into your heart. You do everything that should hurt.

It doesn't. You hate that, and you can't understand why. Shouldn't you be glad that you're invincible? Nothing can touch you!

And, not understanding your reaction, you lie to yourself and pretend you like driving that dagger into yourself. You tell everyone you like it until you are blue in the face. The day comes, eventually, when it stops being a lie. It doesn't inspire indifference in you; rather, it begins to… tickle.

That's when you are evil.

Symbols in my little narrative, in case I confused you:

Scab/heart: emotions, caring, friends, pain, etc. Human.

Painless scab/ cold heart: not caring, selfishness, hatred, whatever. Less human.

Picking at scab/heart: thinking about things that hurt, loving someone who doesn't feel the same, beating your head against a brick wall to do what's right, etc.

Healed scab: healing from an emotional wound.

Stabbing with a dagger: Doing cruel things, attempting to kill your father, tying up cute warlocks named Emyrs, trying to get Arthur killed…

Ticklish sensation: When you are a total freak like Cenred and enjoy causing pain.