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// Posthaste 
// Story: Book 1 - The Behemoth came to Canterlot 
// by Equimorto 
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There was another explosion, like the one moments before but bigger, more intense. Shining was alert, and directed the magic he'd been charging into a shield in front of both him and Cadence. It wasn't a particularly elegant spell, he'd acted too hastily for that, but the amount of energy he'd dumped into it easily made up for that.
The smoke and shadows cleared much more quickly, but both ponies realised it was because Sombra had moved towards them and swept them away in doing so. What he'd turned into had, at least. Where just seconds before he'd looked like a regular pony, the closest to one either of them had ever seen him as, the thing he'd become was much closer to shadow and darkness and only vaguely like a pony in some of its traits. His teeth were more like a lion's or a dragon's, his hooves had been replaced by claws, and he easily would have towered over both of them even if they'd stood one atop the other.
He'd immediately rushed forward and his claws had slammed into the barrier Shining had put up, and Shining thought it was only because he'd used so much magic on it that it hadn't cracked under the impact. Realising his charge had been abruptly stopped, Sombra growled and stared at the two ponies. There was a frenzied look in his eyes, all the reason of the pony who'd been talking moments before gone.
His body turned to shadow again, but it was different from before. A different kind of darkness, thick, heavy, like a giant patch of oil and tar with a will of its own. It pressed itself against the barrier and began to climb it, hurling itself over it. Shining and Cadence both quickly stepped back, and Sombra's body fell to the ground on their side of the shield, where it slowly recomposed itself and regained most of its shape. There was still an indistinct quality to it however, some parts of it remaining more liquid than solid.
Once it had eyes to see again, they immediately settled on Shining. Sombra rushed towards him, faster than anything that size and shape should have been able to move. By all means, his hindlegs were still halfway a shapeless conglomerate on the ground, and yet something that should have been moving by dragging itself around or at best crawling like a slug had reached Shining so quickly Cadence had barely been able to keep her eyes on it.
Shining had put a shield around himself, he had started doing as much the moment he'd seen Sombra crawling over his previous barrier, but still he found himself in trouble. Sombra's body, hitting his shield, had perhaps intentionally lost most of its consistence again. The creature had evidently hurled itself forward with the full intent of striking with its mass alone and not much else. It was quickly taking shape again around Shining's shield however, and that shape was a gigantic mouth with deformed fangs biting down around him and digging into his barrier with each and every teeth. Despite the unicorn's efforts to keep it steady, cracks began to run along the surface of his shield, most of it enveloped by the black tar of Sombra's body.