Xavier Arkwright,
Moses
(temporarily modded with @ConstantlyComic's permission)Moses
Battle Against Castlethulhu, Eastern Field, Fuyuki City
The brief cooldown period that followed after the gargantuan golem's mighty 'punch' was a timeframe probably too brief for any regular human to act in a meaningful or helpful way, yet was enough for several Servants to capitalize on; First, the boisterous Goliath of a man, the one that sported a tiger skin and a musky beard, called forth what was (presumably) his Noble Phantasm - a formidable steed that was almost the size of an elephant! The bearded giant had referred to said equally giant horse as 'Rakhsh', a name that one Xavier Arkwright made a mental note to research sometime later, when his life would be less in peril.
"Caster, what is your current status...? Do you have a way of fighting this thing?" Xavier attempted to telepathically communicate with his own Servant through their familiar link - the currently idle state of the golem allowing him but a very brief moment of tranquility to even try to do so.
"Worry not, Master, I am alive and well..." Caster responded, also telepathically. "However, I'm afraid I do not possess the means to fight this monstrosity." It was regrettable, but true; Even if Caster was willing to use his Noble Phantasm for this fight - something he was extremely reluctant to do when it had the risk of harming the other people in the area as well - it would take too long to take full effect, while the golem was capable of moving much faster. Not to mention, even at full power it was doubtful that Caster's Noble Phantasm would be able to hurt the golem too much. After all, it was designed to harm humans and other living beings, not some larger-than-life stone construct that might not even be 'alive' in the traditional sense. As for Caster's other methods of attacking, it was highly unlikely that they'd be any more effective against the golem either.
It was at that point that a Servant fired a bow at the castle-like monstrosity... an Archer? Miraculously - or perhaps by invoking some kind of power unheard of from conventional weaponry - the arrow managed to actually dent one of the golem's supposedly impregnable shields, yet it did not manage to shatter it... No, that particular feat was accomplished by another Servant - the very same one that had saved Xavier's life mere moments ago - who seized the opportunity and fired an arrow of his own at the golem's already cracked shield, finally breaking it. Was he an Archer too then? Were there not one, but two Archers in this Holy Grail War? How peculiar... From what research Xavier had conducted on the mechanics of the Holy grail War, it should've been impossible for two Servants of the same Knight Class to be summoned at any standard iteration of the time-old ritual.
In any case, the combined assault of the two (possibly) Archers had clearly caused some damage to the Titan-sized golem, as its stone foundations rumbled, as if the monster was crying in pain from the attack. And then something very weird happened... The monster began to twist and malform in itself; It started to shrink from its previously massive size, shields seemingly melting into its body, castle spires morphing into tentacle-like appendages. "It's... transforming..." Xavier couldn't help but stare in mouth-gaping awe at the grotesque spectacle, while the castle-like golem's very form was shifting before his eyes into something completely different...
And then, another Servant, this one a woman of impressive height and stature, also fired an arrow of her own at the monstrosity - trying to hit it mid-transformation, while it was most vulnerable. A third Archer?! What was up with this Holy Grail War...?