Alkyrieaze von Einzbern
"I would not rule out prior tampering... certainly, an incompetent magus might be completely unable to resist some mental strictures. Mentally bind them such that as soon as they try to take a specific action to defuse the situation, they instead unconsciously exacerbate it," the white-haired child interjected, falling back for a second. Hm, those who could interfere with command seals... "The command seals were designed by Makiri Zolgen after the First Grail War proved uncontrollable. I can't say for how the old man designed those used to ensure Heracles' compliance, but I believe that Makiri's design may have redirected some of the energy inherent in the summoning in a form of pseudo magical crest. Three inviolate commands on a Servant, or a potential energy close to Magic."
She supposed that Acht simply went for the "my homunculi have more mana available than any human, copy the idea all over the body" approach.
"Of those founding families, Zolgen--later Matou--are defunct, and the current Tohsaka consists of one individual that I believe can be found in the Clock Tower. Obviously, the Einzbern are uninvolved, otherwise I would never have come here. Those otherwise involved... Kaleidoscope isn't the type but could have the ability, but would be unlikely to have interfered in broad daylight even if he wished to. The former Overseer of the Holy Grail War would have been another possible candidate, as they could acquire leftover seals and redistribute them, but he is also quite dead."
A powerful Caster was far more likely.
Sir Lancelot
The Assassin's response was in the negative--and all the better, as a significantly greater threat had shown up.
How their mysterious enemy had manifested a dragon, even out of shadow... obviously, there were enough Servants here to defeat almost any of the creatures had they shown up--even one as famous as Fafnir. Perhaps something on Nidhogg's level would have normally been a threat... but there were numerous dragonslayers present. This was only a pale reflection.
That didn't mean that should it attempt to escape, it couldn't create untold devastation. If its victims themselves became shadow servants or worse, then it need merely flee to reset the attack again. It would have to be grounded immediately, lest it somehow survive Failnaught in its flight.
The entire plan of which was going through Lancelot's head as he rushed towards the arena proper, coming around from out of the beast's sight and making a great leap--right onto its back. Like any creature, made of shadow or not, its response was to try and rid itself of the sudden weight and needling sensation... of the crosses supporting the knight's cloak digging into its back, granting a brief measure of stability.
A measure long enough for Arondight to swing, the noble phantasm slicing through the dragon's flesh with uncanny ease, the anti-dragon blade vastly reducing the resistance that would otherwise be offered. Not starting at the weak membrane of the wing, but the bone, muscle and sinew, allowing for the limb's own weight to steadily rip it free as the shadow creature tried to beat it in an attempt to dislodge the pest--
The pest, now jumping free to stand apart from the King, forcing the creature to try and focus on two enemies at once, with its own useless, crippled wing dragging on the ground.