u/Adventurous_Sun8074

Image 1 is Zander, second is Nick.

Note that I use the terms darkness and shadows interchangeably. For the purposes of his abilities, they are the same thing.
18 years old

Zander can create and manipulate darkness and form it into whatever he wants. He can also manipulate the properties of said darkness (ex. Making it solid, erase matter, gravitational properties). He can also bring things inside and out of shadows. If he takes something into his shadow, he will gain the ability to make a copy of it out of shadows. The more complex the thing, the longer it will need to remain in his shadows for him to replicate it. He does have to consciously have his shadows open to enter, however, for anything to enter them. 

His strongest attack, aka his divine art is called “Entropic End of Everything,” and it is activated when Zander absorbs all light in the area, turning the area around him to become a void that he can completely control. Inside of this void is similar to being inside of his shadow, which Zander knows everything that’s happening inside of it and he can do almost anything he wants inside of it. (Ex. He can’t move at lightspeed but he can when he’s in his shadow/ divine art). It’s not like a domain where there’s a sure hit, but his attacks move at the speed of light (or perhaps you’d even call it the speed of dark), so they’re still pretty hard to dodge but not impossible. He can also teleport between nearby shadows. 

He can only be killed if you either 

Remove his heart from his body (destroying it wont do anything)

Destroy his right eye or remove it from his body (and then kill him normally)  

Destroy both at the same time

His physicals are all below average human level. He would break his entire arm if he stubbed his pinkie too hard. I guarantee your oc could knock him out with a single punch if he couldn't regenerate. He can augment his durability, however, by covering himself in shadows. 

Speaking of which, he has extremely fast regeneration. His regeneration will stop if you destroy his right eye. 

Zander mostly plays a support role in battles, letting Nick do most of the heavy lifting while he buffs him. He can do things like pulling Nick into his shadows to help him dodge an attack, augment his gravity to make a strike hit harder, block attacks for Nick, opening shadows beneath the opponent to make them trip, etc. He does do a little bit of fighting, however. He can create darkness slashes and beams that erase matter, the beams moving at lightspeed (although they can be anticipated since they appear as black orbs before they start firing), he can also create black holes (usually tiny). Those aren’t all his attacks, just the most common.

Now, it’s time for Nick.

Nick can create crystals out of thin air. He can also choose what kind of crystal he creates, and its properties. Not only that, but he can crystallize and manipulate anything he touches as well. 

His strongest attack, aka his divine art, is called “Crystal Splash.” It creates an indestructible barrier of crystals around Nick and his opponent. When encased, Nick and his opponent are set to the exact same strength and are barred from using any sort of abilities. They will both do the same amount of damage to each other and take the same amount of damage from each other. They have to duke it out until one person loses (getting knocked out, giving up, etc). The loser is impaled with crystals and dies instantly. Yes, this applies to Nick as well. HOWEVER, THIS IS A LAST LAST RESORT! NICK WOULD NOT USE THIS UNLESS ZANDER IS DEAD/DYING AND HE IS DYING AS WELL!!!!!!

His physicals are athlete level except for his durability, which is small building level. His bones are also made of an unknown crystal that pretty much makes his bones indestructible, (it’s just his skeleton, though). He can augment his physicals  if he covers himself in crystals, though. 

He does most of the fighting in a battle. He kind of just uses whatever he feels like in the moment. Sometimes he might create crystal spikes, other times he might crystallize the air and try to freeze you, he could punch you and turn you into a crystal and then shatter you, or he could create a crystal meteor in the atmosphere and stall until it lands on top of your character. His crystals can be extremely durable if he makes them. He usually fights with his fists or creates crystal weaponry. 

Finally, Zander and Nick both know exactly how each others abilities work and they both work amazingly well with each other. They trust the other completely and would also do whatever they could to prevent harm for the other.

The most concrete way, in my opinion, would probably be to kill both of them at the same exact time.

Those aren’t all of his divine protections but don’t worry about the other ones. Solely the ones on the image.