The character could get their power from a god or entity that derives in your universe. Or it could be a accident involving trans dimensional matter allowing them to interact with meta physical energy such as darkness/shadows.

I could do like a dimensional portal that malfunctions or something of the sort.

A black hole doesn't really have anything to do with shadows and darkness... darkness a little since even light can't exist in it but shadow has nothing to do with it.

Maybe have him get hit by a car or something which causes a reaction in his body which then results in him having powers.

Make him a failed experiment or an experiment gone wrong.

1. An independent program that tries to discover some type of phenomena ends up in an accident. The type of phenomena can be anything you desire. As long as it is somehow linked to darkness then it will work. The experiment ends up in disaster and the main character is lucky enough to survive and gain new powers. You can probably come up with a reason as to how he survived.

2. The independent program decides to do testing on people, however the people need to have a specific blood type. Therefore, they use fake orphanages, which your main character is in, that hold many children with a specific blood type. When he is chosen to be experimented on, they accidentally overcompensate and he ends up gaining the power over darkness. You can make up your own particles, so like “The scientists tried to inject small amounts of the particles into him to test him compatibility but the surgeon either made a mistake or bumped into a machine that starts pumping the particles into the body.” Or, you could make is a special liquid. Somehow you can tie this to darkness in some way but it’s difficult. To be honest, darkness powers are one of the hardest to explain acquisition of without having the main character be a “demon” of some sort.

I’ll try to think of better ways.

Either through a failed experiment or he finds an ancient artifact. Honestly, it depends on the personality of your MC.

- Is he a geeky person? Then chose failed experiment like the good old Molecule Man & The Beyonder. The original story is that the Molecule Man gained his powers through failed experiment, This accident pierced through from our universe to "The Beyonder realm" creating a pinhole through which The Beyonder could peer through. And that how Molecule Man gained his vast Extra-dimensional powers and how The Beyonder discover the multiverse.

@13 Apostles comment contain a rich details on how your MC may conduct the experiment +1

- If he is your normal dude then he accidentally finds an ancient artifact of Extra-dimensional origin, and that how your MC channel on Extra-dimensional energy, it's called the Dark dimension.

1 creating minions from shadows

2 teleport from one dark place to another

3 create and control constructs from darkness

4 shapeshifting armor from darkness

5 possession living/unliving objects

For my dark-powered character I made a long time ago, I chose to have a demonic entity with total control over "Darkforce" bond to a kid. That's just something I did. If you want to go the scientific route, have a photon generator go haywire and generate a photon absorption field within your character's body.

@LardWad420 Long time no see dude, did you took a vacation?

Your idea is good, I love the Symbiotic entity friendship.

Nah, I just stopped visiting this wiki for a few days. I'm back and better than ever though!

Good to hear. And yes this wiki start to be boring.