As he whipped around, his gaze met a blur—a Japanese sedan speeding past the alley, followed swiftly by the creature itself. It was a bizarre sight. A humanoid apparition woven from shadows, its long, flowing hair nearly reaching the ground. The shadowy figure towered over even the iron-haired man's imposing frame, reaching a height of nearly three metres.
It seemed to be wreathed in a whirlwind, some sort of bounded field. The air pressure pressed down on him, but it wasn't nearly enough to faze him.
"Nice breeze," he casually remarked to the unknown opponent.
He had no clue of its identity, a Slavic monstrosity summoned mere moments ago, but he understood its nature. An enemy.

Fate/Lost Einherjar, Prologue