Edward's jacket billowed against the wind rushing down the alleyway, buildings blotting out the stars as they seemed to reach forever. Putting his hands together, he braced himself for the assault of the homunculus in child's guise. 
"It's Edward! Where's Alphonse?" Selim acted the exact way he did when they first met, a happy, curious child with a desire for an older brother. Even without the eyes and teeth dotting every tendril of shadow that split from his feet like twisted roots from an ancient tree, knowing the truth behind him made it disturbing instead of endearing. 
"No answer? That's OK, I always preferred you, anyway." He took a step forward, letting the facade drop an inch as his smile resembled a cat with a wounded mouse at its paws. 
The elder Elric was cautious, but not scared. Clapping his hands, a blade extended from his gauntlet, warding off the homunculus's approach. 
"Don't think just because Alphonse isn't here that you can win. There's no way I'm losing to the only person here shorter than me!" He smiled, the big words serving to psyche him up. 
The shadows seemed to shrink, retracting into the youthful homunculus. For a moment, he truly appeared as just a lost child in the alleyway, right up until he raised his head. 
"Oh, so that's all it would take?" It was far more disturbing than his earlier smile, this one a mix between giddy and childish, but with something darker just beneath the surface. 
"What do you think you're-" Edward's words caught in his mouth as Selim continued walking forward, his form expanding as he did so. Every step saw him grow bigger, and soon the concrete beneath him began to shake. Envy was capable of shape-shifting, his true guise that of a massive, hideous creature, but was it truly the same for Pride? Unlike Envy though he was unchanged apart from his size, which now was over twice that of Edward. 
As his mind raced to process what was going on, he had no time to react when Selim now stood directly above the state alchemist, and bending over like a child picking up a toy gripped Edward in his fist, before sitting down, legs crossed.
He gasped, feeling the pressure surrounding him. He tried to struggle, but quickly gave up, accepting it as utterly futile. 
"How? How were you able to grow?" Maybe if he could buy some time, Alphonse would be able to arrive, there was no way he didn't hear or feel the quakes the now-giant young Bradley had created. 
"Grow?" He giggled, holding a free hand to his mouth. It would have been cute, if he weren't a creature made from human souls and currently ten times the size of a tall person, let alone Edward. "Silly, look." He braced himself against the top of his fist as he was whirled around by the boy with a child's care for his comfort. Seeing his reflection staring back at him, he strained his neck trying to look around, as the surface looked familiar. As if reading his mind, Selim spoke up. 
"Too close? Here, try this." Scooting back, Edward turned white upon getting a better view. It was a metal trashcan. Selim hadn't grown, he had somehow shrunk! 
"Do you get it now? Of course you do, you were always smart. It's one of the reasons I idolized you, you know?" Turning him back around to face him, Ed offered no resistance. To think that the homunculi had powers like this? 
"Growing is inconvenient, especially when you're supposed to play the part of a cute, innocent, helpless little boy. But if a few people go missing every now and again, well, what's a boy without a few toys?" 
Edward went rigid. Missing persons weren't uncommon, but never his department. To think that... "You're responsible for all of them?" He growled. 
Selim raised a hand in mock-surrender, as if the doll-sized alchemist was any real danger securely confined in his fist. "Of course not *all* of them, at the end of the day no one is worse to humans than other humans. Just a few, ones nobody would miss. I have to say, you'll be the first I care about." Opening his hand, he set the other to pinch his coat, pulling it off of the stubborn alchemist, despite his vocal protests. As he made to take off the rest, the tiny alchemist's hands made the circle, and with the blade from his gauntlet lengthened he slashed at the monster in human skin.
“Ow! E-Edward...” Selim sniffled, a large scarlet bead growing from the cut inflicted upon his thumb. 
He cursed himself for it, but seeing the colossal young boy whom he had entertained in his state manor tear up from that minor cut was all the hesitation the homunculus needed.
Snatching both pieces of his automail inbetween separate fingers Pride laughed. “You really thought you could ever hurt me, especially at such a pitiful size?” The blood burned away in red sparks, and with it any hint of damage Edward had been able to inflict beneath. “Still though, that was very naughty. A toy has no right hurting his master, now does he?” The last line was delivered with that look that tingled the alchemist's spine, that face that only one who was aware of his true nature would see monster shining through Selim's innocent face. 
Collecting himself, the elder Elric was set aflame at being called something beneath even shorty, and spat, “A what!? I'll!-” His words were cut off as the pressure on his automail began to increase, quickly exceeding the pressure limits Winry had built into them as evidenced not only by the squealing of metal, but the intense pain shooting through his torso, as if it were his own, real limbs that were being pinched. 
Then pulled. At this point Edward yelped out in pain, struggling futilely against the child-monster's thick, powerful fingers. He couldn't be-
“Stop, stop! What are you doing!?” Tears stung his eyes, the physical pain was bad, but it was losing his limbs again, and in such circumstances that caused the state alchemist to crack. 
“Pride! Alphonse! Selim, plea-” The automail was torn away, and the flesh celebrated its freedom with a ragged, bloodcurdling scream, raw with agony and loss before quieting to a sickly, wet gurgle as Edward fell limp, unconscious and defeated by the homunculus Pride.
Pride looked around, slinking into the shadows, some natural, some woven by him to ensure he wouldn't be spotted. 'Big brother' made a shocking amount of noise for his size, though given his treatment... 
Blood oozed from the stumps of where his automail used to be, torn out down to the screws. Lifting his limp body up like a discarded doll, he snaked out his tongue to catch some of the nectar. 
“It's strong, but still just as sweet as you are, big brother....” He licked his lips as his stomach growled. His consumption of Gluttony had left him with an appetite and an expanded pallet, but... “...Not yet, I want to play with you more first.” Gently touching the limp Elric's wounds, they sealed with the same red sparks that had closed his own exceedingly small cut on his thumb earlier. 
Needing to keep his new prize hidden as he made his way back to the manor, he tucked the unconscious alchemist into safety, a light blush painting his cheeks as he hurried home like a good boy.