Bound by surprise

Tinned food?

It was - Hayden decided - the worst day he had ever been forced to endure.  In all his twenty years on the Earth their had never been anything that came close (though he thought  really in the span of things twenty years isn't even a speck).
First his friend had cancelled on him then the shelf that held the gift he was going to give to aforementioned friend fell on top of him.  That was how he ended up at the A&E and then the department store with an obnoxiously blue cast on his left arm -thank whatever it is that dictates the law of the universe that it wasn't his right.  He had decided he needed to buy another present - it would be childish naivety to believe the delicate glass ornament would have survived being crushed underneath the weight of the shelf and everything on it as well as his own.  "Great." He muttered bitterly as he searched the barren shelves for anything that would be even somewhat suitable to give to a wealthy heiress as a gift.  "Just brilliant!" His words were venemous and his facial expression could cut.  His emerald eyes fluttered closed in frustration and he leant backwards with his right hand stuffed into his jean pocket.  Then the loud clattering of the pyramid of tin cans behind him filled his ears.

Niyah had learned long ago that trying to deny a summon from the king was pointless - she had been dragged out of Caelum kicking and screaming like a child throwing a tantrum more times that she'd care to admit.  It was always the same reason - it was the price one payed for utopia - someone was about to die where she had all those years ago.  She was one of the lucky ones.  She had died in the middle of nowhere, only about once a century was she forcefully removed from paradise - poor Billy had died in a car crash where he had been sent over the railing of a mountain road and he was gone so often she could have sworn he spent more time Mundus than in Caelum.
But of course everything had its disadvantages - Murphy's law - she was so unaccustomed to the deaths she saw that she couldn't just watch like a hapless spectator; she had to at least try to be the hero.  Of course humans couldn't see her, they could not see what was beyond their level of comprehension.
The boy was nothing special.  He stood out among the steely grey of the store but he was not the kind to rush to your aid in battle.  His hair was a shock of fiery ginger and his skin was practically translucent, irregularly littered with freckles.  He was probably twice her height but maybe half her weight.  His eyes were closed and it was practically slow motion, he fell back into the falling wall of food.
Niyah couldn't even consider the ridiculousness of the death the youth was going to suffer as she rushed to his side in false optimism. 
Astoundingly, her hand connected with his cold, bare arm.  She didn't even have time to comprehend just what was happening as she dragged him forward faster than any human could.  He swayed in a daze before lowering himself to a crouch and bringing his bony legs up to his chest. Not sure what to do, Niyah just hovered over the form of the boy who's life she had saved as his ragged breathing began to settle.  She stared at the weird blue casing on his arm as his entire body shook and shivered.  She took the time spent in awkward silence to observe just how much people had changed in the last century.  Fashion had changed spectacularly - she even saw a girl wearing trousers - the boots he wore were militaristic and there were rips in the weird black trousers he wore.  There was a thin copper chain around his neck and his shoulders and arms were completely exposed by the shirt he wore.  There was a vine-like design printed in black ink that twisted from his clavicle to his wrist.
Then he looked up.  There was something off about those eyes though.

The girl that stood in front of Hayden was pretty but undeniably old fashioned.  Her fashion sense was outdated by centuries - maybe even millenia - rather than years or decades.  Her skin was a dark chocolate brown and her hair was woven  into immaculate cornrows.  Her ears were gaged and there were geometric tattoos that occasionally coloured her skin.  Her eyes were like onyx,  gazing at him fiercely in an odd combination of fear, concern and curiosity.
"Are you okay?" Her voice was melodic and warm but strangely empty and echoey.  It sounded as if she had said the words a minute ago into a cave but he was only just receiving them.
"Umm... yeah.  I - I think?" He couldn't make eye contact, he never could but the unnerving depth in her eyes did not help.
She offered him a hand, which he rook graciously and used it to pull himself onto his size 13 (UK size) feet.  He towered above the petite girl.  She was maybe four foot 6, he had given up on counting when he hit seven foot.  He offered her an awkward thanks which she accepted distracted as her face scrunched up in thought.  Her head tilted to one side and her mouth was pushed to the other.  Her nose was crinkled up as if she had smelled something repugnant and her thick eyebrows were lowered to the tops of her wide eyes.  She was distracted clearly, her response to his gratitude was a slight flick of her wrist.  He pushed his unruly hair from his face where it had fallen in sweat drenched tendrils as a result of his earlier panic.  That was when the look in her face morphed from confusion to realisation to anger before returning back to confusion.  "What?" He cared to ask.
Her only response was a near inntelligible mutter of what sounded suspiciously like "Impossible."

Finally Niyah realised what had been bovering her so immensely about the boy and his strange eyes.  Those were the King's eyes inserted into a pale, gaunt face that they clearly didn't belong in.
Next was the mystery of -how can he see me?